Abstract:
On October 2, 2021, Sound Transit of the Puget Sound region of Washington state started Link light rail service to three new stations on the 1 Line . These stations serve the University District, Roosevelt, and Northgate in Seattle. In coordination with the station openings, Sound Transit, King County Metro, and Community Transit of Snohomish County restructured many of their routes that had previously provided express service to downtown Seattle and the University District. This report examines the changes in travel behavior that occurred as a result of those change in transit service. Comparisons are made primarily between September / October 2019 (the last pre-Covid-19 year) and September / October 2021.

Authors:
Hallenbeck, M.E., Hager, G., Avery, R.

Keywords:
Transit service, light rail, travel behavior, planning, transfer

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Abstract:
The Washington State Commute Trip Reduction law requires worksites with 100 or more full-time employees who begin their shift between 6:00 and 9:00 a.m. on weekdays to conduct a biannual commute survey. Commute Seattle has led this survey work since 2010, and in partnership with the Downtown Transportation Alliance, it has used the results to measure progress toward the city\\\'s mobility goals. In 2022, Commute Seattle joined the University of Washington’s Mobility Innovation Center and the Department of Urban Design and Planning to improve and expand upon the survey and evaluate current transportation systems. The results give transportation planners a clearer picture of travel trends in relation to demographic groups, employment types, and housing.

Authors:
Shen, Q., Ashour, L., Moudon, A.V., Treece, B.,

Keywords:
Commute, CTR, Mobility, Telework, Seattle

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Abstract:
Public agencies can take a leading role in supporting transit-oriented development (TOD) by making land available to developers (selling or leasing land, potentially below market prices). With existing access to transit systems and often large land areas, park and rides that are publicly owned can be leveraged to support TOD uses, such as affordable housing, office space, small businesses, and mixed-use buildings. To effectively support TOD planning, this research developed a multi-criteria prioritization tool to identify the most promising locations for TOD and tested it at three park and ride sites owned by the Washington State Department of Transportation. The tool was developed through the Delphi process, which is an effective and inexpensive approach for evaluating relevant indicators by synthesizing the opinions of experts from various backgrounds. Five categories with a total of 14 TOD indicators, including transit supportive land-use zoning, job accessibility, land price, land-use mix, and household income, were selected as measures of TOD suitability. The importance of these indicators varied with three different TOD scenarios: (1) emphasis on affordable housing, (2) emphasis on market-rate housing, and (3) emphasis on mixed-use development. Using the calculated suitability scores, this tool can prioritize potential TOD sites for further review.

Authors:
Shen, Q., Acolin, A., Moudon, A.V., Cai, M.

Keywords:
TOD, Delphi Method, multi-criteria planning tool, multi-sources geospatial data, publicly owned land

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Abstract:
Recent emphasis on actions to reduce large-scale greenhouse gas (GHG) emissions has pushed most state departments of transportation (DOTs) to develop carbon accounting practices compatible with their current standard data collection and storage practices. In particular, with the recently passed Buy Clean Acts in California, Colorado, and Oregon and the recently proposed Buy Clean and Buy Fair Washington Act, common construction materials such as cement concrete, steel, and asphalt are now under special attention. Once accurate and reliable accounting of GHG emissions has been established, strategies can be formed that will help mitigate the adverse environmental impacts of materials that state DOTs utilize. This project, in collaboration with WSDOT, is an attempt to perform a lifecycle assessment (LCA) on some of its agency-wide operations that emit GHGs. To date, WSDOT has not conducted comprehensive research on the embodied carbon within its construction material usage (i.e., an upstream Scope 3 emissions inventory), with most previous carbon accounting practices being focused on Scope 1 and Scope 2 emissions (i.e., the carbon footprint of direct and indirect energy usage). Although several strategies are now in place to cut Scope 1 and 2 emissions, such as the use of alternative and renewable energy sources, strategies to reduce Scope 3 emissions have neither been fully recognized nor quantified. Therefore, this project used several data sources from WSDOT in conjunction with lifecycle emission factor data to estimate GHG emissions from the materials used to build and maintain roadways under WSDOT’s jurisdiction. We found that upstream Scope 3 emissions for WSDOT as an agency are a big contributor to its overall carbon footprint by a five-year average of 310,000 metric tons of CO2 eq. This project further suggested carbon reduction targets for WSDOT and provided recommendations to achieve GHG reduction targets of 50 percent below the 2020 baseline in 2030 and 90 percent below the 2020 baseline in 2050 through decarbonization scenarios.

Authors:
Simonen, K., Ashtiani, M., Lewis, M., Huang, M.

Keywords:
Embodied carbon, greenhouse gas emissions, lifecycle assessment, hot mix asphalt, cement concrete

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Abstract:
This report documents the results of a statewide community outreach effort designed to help inform the Washington State Department of Transportation (WSDOT) about the spending priorities of state residents as part of WSDOT’s ongoing update of the Highway System Plan. The report documents the outcome of a statistically valid, statewide, discrete choice survey. In the survey, residents were given a hypothetical constrained budget and asked to allocate that budget across multiple funding categories. Survey respondents were allowed to select between multiple options for each funding category and were given information on the expected outcomes from each of those funding levels. The results were analyzed by geographic region of the state and by socio-demographic characteristics of the respondents. The responses documented in this report provide key insights for the plan’s update.

Authors:
Hallenbeck, M.E., Brown, R., Moudon, A.V.

Keywords:
Survey, Highway System Plan

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Abstract:
The impacts on bridges of a magnitude 9 (M9) Cascadia Subduction Zone (CSZ) earthquake were evaluated to help prioritize earthquake retrofit efforts and support the development of emergency response plans. To evaluate these impacts, researchers developed single-degree-of-freedom (SDOF) models of typical pre-1976 and 1976-2018 bridges in Washington state. These models were subjected to ground motions from 30 simulated M9 scenarios, ten locations, and four sets of 30 site profiles. The mean calculated lateral strengths of the older and newer bridges were similar for a wide range of periods and exceeded the strengths expected from design procedures, even after the contributions of the abutments were neglected and material overstrength was accounted for. As expected, the older bridge columns had far less transverse reinforcement than the newer bridges. Near the CSZ, the damage was predicted to be widespread for a wide range of effective periods. The likelihood of column concrete spalling and longitudinal bar buckling ranged from 35-70 percent and 10-30 percent, respectively, with the larger values corresponding to softer site profiles. Far from the CSZ, the flexural damage to bridges was expected to be slight for locations outside of sedimentary basins. For most locations within sedimentary basins, such as Seattle, damage levels were predicted to be low for bridge periods below 0.5s. For bridges with periods of between 0.5s and 3s, the likelihood of concrete spalling ranged from 50-75 percent. For these long-period bridges, the likelihood of bar buckling ranged from 35-50 percent for softer sites and 20-35 percent for stiffer sites. This study did not account for the effects of bridge abutments, skew, or curved alignment. Note also that this study did not consider the possibility of span unseating, column shear failures, or site liquefaction, any of which could lead to bridge collapse.

Authors:
Eberhard, M., Kortum, Z., Liu, K-J, Berman, J., Marafi, N., Maurer, B.

Keywords:
Bridges, earthquakes, Cascadia, damage

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Abstract:
Shotcrete is becoming popular for vertical and overhead applications where conventional formwork and repairs are difficult and costly. However, the substrate and the shotcrete overlay interface can be vulnerable, and the bond properties in this region are not well understood. Furthermore, the interface bond could be adversely affected by long-term freeze-thaw weathering in northern states leading to debonding from the existing substrate and corrosion of rebars. Hence, characterization of the shotcrete-substrate interface bonds is critical for the performance evaluation of shotcrete construction. To this goal, this study evaluated the shotcrete-concrete interface bond using four representative substrate surface preparation methods: chipped, pressure-washed, sandblasted, and as-cast, under three different loading conditions: tensile, shear, and Mode-II fracture. The study also investigated the long-term freeze-thaw durability of these bonds and introduced a probabilistic damage model to predict their service lives. The estimated surface texture depth and bond behavior are also correlated using laser texture scans of the substrate. Results indicate that the chipped substrates led to the highest interface bond strength and mode-II fracture energy. Out of the remaining surfaces, pressure-washing produced an interface bond that is more tensile-resistant, whereas sandblasting led to an interface bond that is more shear-resistant. Therefore, it is recommended to consider the actual loading application on the shotcrete-concrete interface bond when choosing appropriate surface preparation and testing techniques. Recommendations were proposed to include in the shotcrete specifications. Specifically, a tensile bond strength of minimum 145 psi from a direct tensile bond strength test (e.g., ASTM C1583) is recommended for overhead shotcrete application and a shear bond strength of minimum 300 psi from a direct shear bond strength test (e.g., AASHTO T323) for slope stabilization with shotcrete. Substrates with minimum estimated surface texture depths of 0.294 mm or larger (based on ASTM E2157 or D8271) or ICRI CSP No. 4 or higher led to bond strengths greater than 145 psi as specified by ACI. However, the predicted service life of shotcrete-concrete interface bonds is significantly reduced in regions prone to a higher number of freeze-thaw cycles. Therefore, methods to improve the long-term durability of bond strength need to be further investigated.

Authors:
Wen, H., Qiao, P., Manawadu, A.

Keywords:
Shotcrete, substrate to overlay, surface preparation, interface bonds

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Abstract:
This report examines Long-Term Pavement Performance (LTPP) database users’ needs for traffic data and parameters and the extent of traffic data availability in the LTPP database. It identifies and recommends new analysis-ready traffic parameters and traffic data–usability indices for inclusion in the LTPP database. This report also presents a methodology for computation of analysis-ready traffic parameters selected by the Federal Highway Administration for this study and a methodology for assessing reasonableness of historical axle loading data included in LTPP database tables for sites that do not have sufficient information about the accuracy of equipment used to collect these data. This report includes a description of LTPP database tables that include newly computed analysis-ready traffic parameters. For LTPP sites that do not have traffic data, this report explores alternative data sources and provides recommendations for using these data sources. This report includes an overview of the User Guide for Selecting and Using Long-Term Pavement Performance Traffic Data, which aims to help LTPP database users navigate and understand LTPP traffic data and parameters and select or compute traffic parameters that best fit their project or analysis needs.

Authors:
Hallenbeck, M.E., Selezneva, O.I.

Keywords:
Traffic data, traffic loading, pavement design, Long-Term Pavement Performance, MEPDG, WIM, weigh-in-motion, HPMS

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Abstract:
Targets and measures are key components of roadway performance management and are critical to communicating information about the transportation system to decision-makers, stakeholders, and the traveling public. Target setting for travel time-based measures has emerged as a challenge in transitioning to a performance management-based approach for making transportation investment and policy decisions, as mandated by the Moving Ahead for Progress in the 21st Century Act (MAP-21) and the Fixing America’s Surface Transportation (FAST) Act. This report provides potential approaches and resources to state departments of transportation and local agencies to help overcome those challenges. Approaches include technical options for developing the information to support target setting.

Authors:
Hallenbeck. M.E., Lindsey, C., Motamed, M., Margiotta, R.

Keywords:
Performance management , transportation investment, policy, target, target setting, stakeholders

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Abstract:
This study investigated the design and feasibility of noise mitigation strategies for installation in modular expansion joints (MEJs), with a focus on Washington state’s SR 520 bridge. The three main sources of noise from MEJs include resonance of the air within the gaps, resonance of the beams, and resonance of the tires. By filling the gaps in the MEJs with engineered chevron support structures we have shown that it is feasible to significantly reduce the noise from MEJs. We performed both experimental and computer evaluations of a noise attenuation system before performing limited testing on the SR 520 bridge. Installation of the treatment on one westbound lane of the east MEJ of the SR 520 bridge proved to be highly effective over the two-month test period. At a distance of 160 feet, we measured a more than 70 percent reduction in audible noise over the noise of background traffic throughout the testing period. Beyond 160 feet the difference between noise from the concrete road surface and from the MEJ became so small that it became very difficult to identify when individual cars crossed the MEJ. While we have shown that the chevron system can be an effective solution to the expansion joint noise issue, we outline further development and testing to extend the durability of the treatment.

Authors:
Reinhall, P., Lipton, J., Thomas, S., Elmadih, W.

Keywords:
Bridge, Expansion joints, Noise control, Noise sources, Sound attenuation, Testing

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Abstract:
Advances in battery-powered electric motor systems, lightweight materials, and aircraft design have resulted in the development of new electric aircraft that could gradually replace conventional fuel-powered aircraft for certain uses in the coming years. In addition, a whole new category of electric vertical takeoff and landing aircraft has received billions of dollars of new investment, with the goal of serving an entirely new urban air mobility market that would allow for fast trips within congested metro areas. This study developed methods to estimate plausible future energy and power demand for electric aircraft operations at regional airports to determine whether the electric grid near two regional airports, Paine Field and Grant County International Airport, have the capacity to serve the potential energy (MWh) and peak power (MW) needs of electric aircraft operations over the next one to two decades. Our method has three parts: assumptions on flight operations growth, technical feasibility to serve these flights with electric aircraft, and actual adoption of electric aircraft to serve feasible trips. We found that the electric utilities serving these two airports have enough electric capacity at the neighboring substations to meet the demand for electricity over the next decade, given the capacities reported by the local utilities. Experience gained in the first decade of commercial electric aircraft deployment at these airports will help inform future analysis as to whether local grid capacity will eventually impede the growth of electric aircraft charging. Lastly, the report presents recommendations on how regional airports can prepare for electric aviation.

Authors:
MacKenzie, D., Coenen, S., Malarkey, D.

Keywords:
Electric aviation, electricity, projection, electric vertical take-off and landing, eVTOL, Paine Field, Grant County International Airport, Washington state

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Abstract:
Pedestrian safety is a priority of Washington State Department of Transportation’s (WSDOT) Target Zero Plan. This report provides the findings of the data used and the models developed to support our understanding of pedestrian safety. The project used data from WSDOT, the Census, the King County GIS Center, the University of Washington Urban Form Lab, and National Historical Geographic Information. The models created aimed to (1) identify factors and locations in Washington State that are associated with a higher number of pedestrian-vehicle crashes (frequency models) and (2) explore factors that contribute to pedestrian-vehicle crashes that result in serious injuries and fatalities (severity models). The outcome of interest for the frequency models was the number of pedestrian-vehicle crash(es) per 100-meter Euclidian buffer around intersection and non-intersection locations on state routes in King County, Washington, and in the entire State of Washington. Mixed-effects Poisson regression was used for these frequency models because the mean and variance of the outcome variable were not significantly different. The state route variable was treated as a random intercept to account for pedestrians’ characteristics that were specific to each state route. Microenvironmental factors that were positively correlated with the frequency of pedestrian-vehicle crashes included intersection type (intersection or non-intersection), being on a principal arterial road, total width of lanes, presence of a park and ride facility, and commercial area. The findings suggest that locations with these characteristics should be considered during rankings of locations within the pedestrian subcategory of the WSDOT I2 – Safety Program. Macroenvironmental factors (measured in a 400-meter buffer) that were negatively correlated with pedestrian-vehicle crash frequency included area household income and industrial land use. Higher-income households were related to a lower number of pedestrian-vehicle crashes, suggesting that reduction in crash potential should consider including identifying low-income neighborhoods. The Washington State model also accounted for state routes as a random effect. As expected, state routes within King County (SR 99, I-5) showed a higher number of pedestrian-vehicle crashes per 100-meter buffer. Binary logistic regression models were developed to examine the likelihood of pedestrian-vehicle crashes that result in serious injuries or fatalities. Older pedestrians (age groups: 45–64, 65–74, and 75+) involved in crashes were more likely to suffer serious injuries or to die than pedestrians in the age group 25–44. The likelihood of a pedestrian-vehicle crash resulting in serious injury or fatality increased when pedestrians failed to grant the right of way to vehicles, when drivers were moving straight ahead, and under dark light conditions. Crashes occurring on roads with speed limits higher than 40 mph were more likely to result in severe injury or fatality, while crashes occurring in park and ride lots and in areas of higher population densities were less likely to result in severe injury or fatality. Police crash reports often lacked information on vehicle speed, and pedestrians’ and drivers’ actions at the time of a crash. Complete and accurate crash reports will provide greater insights to enhance pedestrian safety.

Authors:
Boyle, L., Moudon, A.V., Haena, K., Mingyu, K.

Keywords:
Pedestrian safety, Pedestrian-vehicle crashes, Crash frequency, Crash severity, Regression models, Injury prevention, Geographic information systems

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Abstract:
This project developed recommended changes to the state’s Public Records Act that will enable the state’s public agencies, cities, and counties to obtain and use a variety of new electronic data—often collected by the private sector—that describe transportation system use of individuals, vehicles, and companies, without releasing to the public detailed data that could compromise the privacy of individuals and the trade secrets of companies. The State of Washington’s Public Records Act (PRA), passed as a public initiative in 1972, was designed to provide more transparency in the decision-making process at all levels of government. The law also directly acknowledges that citizens have privacy rights that deserve protections. However, the current version of the PRA was not written to account for the ways that modern technology has changed the collection of data and how those data are used for business applications and to manage the transportation system, as well as how unscrupulous individuals can abuse those data. This amendment should clarify privacy and trade secret protections of individuals and companies within the law, while maintaining transparency in government decision making, and should remove barriers to the sharing and use of private sector data to enable public agencies to more effectively manage the transportation system.

Authors:
Hallenbeck, M.E., Spitzer, H., Collins, B., Porton, A., Glaser, D.

Keywords:
Public records, Privacy, Transportation data, Transportation operations

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Abstract:
This report provides a framework that can be used to develop an evaluation of technology applications designed to remove barriers to transportation for people with visual, hearing, cognitive, and mobility disabilities. The framework helps evaluation teams follow a consistent process that starts with an understanding of 1) the goals of the technology; 2)the needs of the intended user population; and 3) the intended technical performance of the system, to create a logic model that identifies the evaluation hypotheses to be tested, the appropriate performance measures for evaluating those hypotheses, the data sources from which the required data can be obtained, and the areas where collaboration and agreement are needed between the evaluation team, the technology developers, and the evaluation sponsors to finalize and perform the evaluation. The framework specifically accounts for—and provides guidance for—evaluations of a wide variety of accessibility development projects (ADP) and is designed to help project sponsors, participants, and independent evaluation (IE) teams focus their evaluation efforts on the key outcomes of importance for each ATTRI-funded ADPs being studied, while also keeping in mind the need to understand the effect the ADP has on overall trip making capabilities of users. Thus, the framework is designed for use with all types of projects sponsored by U.S. Department of Transportation’s (USDOT) ATTRI Program.

Authors:
Caspi, A., Hallenbeck, M.E., Tyman, S.

Keywords:
Wayfinding, Pre-trip, Scenario, Logic model, Accessibility development projects

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Abstract:
This document provides decision making guidance that highway agencies can use to purchase or acceptance test traffic volume estimates such as annual average daily traffic (AADT) from the private sector when those estimates are based on non-traditional data sources, such as vehicle probe or smartphone data.

Authors:
Hallenbeck, M.E., Schewel, L., Co, S., Wergin, J.

Keywords:
AADT, probe data, volume, Big Data, LBS, GPS, machine learning, MADT, volume, AADTT, K-Factor, D-Factor, AAHT

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Abstract:
This project investigated the hydrodynamic causes of severe erosion at the Washington State Ferries ferry terminal in Kingston, Washington, where a cliff-like bathymetric feature had shifted shoreward in recent years, forcing repairs on the slip\'s bridge pilings. High resolution measurements of velocity and estimates of turbulent bed stress were taken during vessel arrivals and departures during two deployment periods in March and April 2018. Calculated bed stresses (and maximum velocities) were found to be 10 to 100 (30 to 50) times larger during vessel arrivals and departures than background levels. The structure of the wash was modified by the bathymetry such that steeper bathymetry led to more reflection of the propeller wash. Bed stresses were higher during vessel departures than arrivals, corresponding to higher vessel acceleration during departures. Additionally, during departures, lower tidal states corresponded to higher bed stresses because the propellers were closer to the seabed. During arrivals, larger vessels generated higher bed stresses. In this work, we developed, assessed, and used an empirical model for bed stress that took into account these dependencies. Using this model, we determined that the most important factor for cumulative vessel stress is the frequency of use of a given slip. Additionally, shallower ground lines will be exposed to higher bed stress than deeper ground lines, so modifications to the existing bathymetry should take into account both the effect of shallower depth and milder slope.

Authors:
Kastner,S., Stearns,C., Horner-Devine,A., Thomson, J.

Keywords:
Hydrodynamics, wakes, turbulence, scour, ferry terminals, vessel operations

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Abstract:
Sound Transit and King County Metro teamed as sub-recipients on a project led by Los Angeles Metro to demonstrate the viability of a partnership with a private sector transportation network company to increase access to transit through the provision of on-demand, first-mile/last-mile transit access services. This independent evaluation report concentrates on the actual ridership impacts of the Via to Transit service; that is, how many people chose to use Via, whether those individuals represented all segments of the population living in the study area, and whether the availability of the Via service for first-mile/last-mile trip making changed their use of Link light rail or bus.

Authors:
Hallenbeck, M.E., Van Roijen, A., Avery, R., Zyuzin, D.

Keywords:

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Abstract:
The Pacific Northwest has seen a reduction of fish populations related to the number of fish barriers in the area. In response, Washington State implemented new design policies in 1999 to replace the most common barriers, culverts. New “stream simulation culverts” incorporate a sediment lining, providing an environment more conducive to fish movement. Streambed design must balance engineering and ecosystem factors, but there is little guidance on how to maximize the lifespan of the overall channel shape while providing maximum fish passage during low water flows. This research investigated how to incorporate coarse material (coarse bands and boulder bars) into a simulated streambed in a flume. The first objective examined whether coarse bands and boulder bars could stabilize a channel without eliminating sediment transport. Three characteristics were tested: coarse material size, the number of coarse bands, and the spacing between coarse bands/boulder bars. The second objective was to investigate relationships between the number and spacing of coarse bands/boulder bars and channel stabilization. Streambeds were subjected to one-, two-and-a-half-, five-, and ten-year flood frequency events. Sediment transport was quantified after each flood event by using cross-section profiles and was analyzed to determine net change for each cross section. Thirty coarse bands and twelve different boulder bar configurations were tested with variable numbers of coarse bands/boulder bars and amounts of spacing and stream slope relative to a uniform streambed (without coarse bands). The research showed that nearly linear, coarse bands that fully spanned the channel reduced sediment transport by 56%, 54% and 50% at bed slopes of 2%, 3%, and 4%, respectively, conditional to differences in the geometry of the coarse bands at each slope. Boulder bars spaced one channel width apart produced sediment transport reductions of 49%, 57%, and 33%, at bed slopes of 2%, 3%, and 4%, respectively, and produced different transport patterns than the linear designs. These findings indicate that minimal additions of coarse bands reduced sediment transport and generally maintained U-shaped channels. Coarse band/bars at greater bed slopes required larger material and armoring layer downstream to prevent destabilization/failure.

Authors:
Engdahl, N., Fouty, T., Kelty, B.

Keywords:
Coarse bands, stream simulation design, water resources, fish barrier, sustainability

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Abstract:
The durability performance of asphalt concrete (AC) with various percentages of reclaimed asphalt material (RAM) has been a focal point of the asphalt industry, leading it to embrace the balanced mix design (BMD) concept. The goal of this research was to review and enhance WSDOT\'s AC materials selection, mix design, and standard specifications for optimized use of RAM, based on readily implementable technology, in collaboration with industry stakeholders for improved durability performance. The scope included a literature review, an assessment of RAM supply in the state, and a statewide comparison of low and high RAM pavement performance data to determine whether differences were observed;. The scope also included an evaluation of raw materials and field mixtures and an evaluation of laboratory mixed-laboratory compacted (LMLC), field mixed-laboratory compacted (FMLC), and field cored (FMFC) samples. The laboratory analysis included short-term and long-term aging of binders and mixtures with rheological and cracking tests performed on them. One recommendation of the study was to integrate volumetric parameters along with further performance testing in a BMD approach to increase effective binder content. Another was to implement all of the volumetric criteria in AASHTO M323 during mix design, test section and acceptance. Additional recommendations were to use ΔTc as an aging parameter in binder specifications; include RAM in all mix designs regardless of doses; maintain an IDT strength specification and transition to the CT-Index; add long-term aging for IDT/CT-Index test specimens in the future, maintaining the current Hamburg Wheel Track (HWT) rutting test and criteria; revise short- and long-term standard specification; and re-evaluate the performance of RAM pavements with time.

Authors:
Muench, T., Hand, A., Sebaaly, P., Hajj, E., Chhetri, K., Piratheepan, M., Elias, N., Howell, R., DeVol, J., Davis, S,

Keywords:
Asphalt concrete, performance, recycled asphalt materials, durability

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Abstract:
This report documents the results of a literature review and methodological analysis into the design and technical basis of the QUEWZ work zone road user cost estimation software tool. The report documents how key formulas/algorithms within the QUEWZ software were derived, describes ways that QUEWZ could be updated, and summarizes the literature regarding comparisons of QUEWZ with other tools used to evaluate work zone road user costs.

Authors:
Ishimaru, J., Hallenbeck, M.E.

Keywords:
Construction traffic, Construction traffic delay estimation, QUEWZ, HCM, Work zones

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Abstract:
Wood guardrail posts can be inspected for decay using a non-destructive testing (NDT) technique called stress wave timing (SWT). This project conducted a field investigation on approximately 500 wood guardrail posts using SWT and then analyzed available data to determine factors that may lead to increased wood decay rates. It was determined that locations with high climate index (> 40) experienced higher decay rates. Additionally, poor preservative retention levels were also found to be associated with high decay rates. Impact testing concluded that decay reduces the fracture resistance of wood posts by more than 50 percent. The results of this report will be useful in considering approaches to managing WSDOT guardrail assets in the future.

Authors:
Phillips, A., Luo, Q.

Keywords:
Nondestructive testing (NDT), Stress wave timing (SWT), Wood, Guardrail, Pendulum impact testing, Fracture energy

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Abstract:
Using data on each trip made on the I-405 express toll lanes during all operational hours (weekdays 5:00 AM – 7:00 PM) of 2018, demographic data by census block groups, plus speed, volume, and travel time data for both the express toll and general purpose lanes, this study examined how the express toll lanes are used, the benefits they provide to users, and how these benefits are distributed among different groups of noncommercial users. The project used data from over 16 million trips on the facility. The result is unique insight into facility usage patterns and equity impacts associated with different income and geographic groups.

Authors:
Hallenbeck.M.E., Leung, S., McCartan, C., Robinson, CJ, Zamir, K.R., Iverson, V.

Keywords:
Express lanes, Toll lanes, HOT lanes, Elasticity, Equity, Usage

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Abstract:
Like many congested cities, Seattle has experienced a rapid increase in ride-hailing trips by transportation network companies (TNCs) such as Uber and Lyft. That increase has raised broad concerns about congestion, safety, and effective curb use. In response, this study looked at a strategy to manage TNC driver stops and improve traffic flow when passengers are picked up and dropped off in the South Lake Union area of Seattle. To mitigate the impacts of passenger pick-up/drop-off activity on traffic, the city proposed a strategy of increasing passenger loading zone (PLZ) spaces in South Lake Union, while Uber and Lyft would implement a geofence to direct their drivers and passengers to designated load and unload locations. The study found that passenger loading and unloading made up a significant share of total vehicle activity in the study area. Without dedicated load/unload curb space, TNC vehicles stopped and waited at paid parking spots and in other unauthorized curb spots. A significant percentage of vehicles also stopped in the travel lane, potentially blocking or slowing traffic. Adding PLZs and geofencing was found to increase driver compliance in stopping at the curb versus stopping in the travel lane to load/unload passengers. Adding PLZs and geofencing also reduced the average amount of time drivers stopped to load/unload passengers. In addition, adding PLZs and geofencing did not have a significant impact on traffic safety, and it did not produce a significant impact on roadway travel speed.

Authors:
Goodchild,A., MacKenzie, D., Ranjbari, A., Machado, J., Dalla Chiara, G.

Keywords:
Parking, curb, transportation network companies, passenger load zones

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Abstract:
A relevant literature review was conducted of best practices related to the use of the linear scheduling method (LSM) for heavy civil construction projects. The comprehensive literature review revealed an additional need to understand how LSM could be best utilized for WSDOT, which will include conducting an investigation into off-the-shelf software programs that could be integrated with existing platforms that WSDOT currently uses.

Authors:
Kim,A., Wang,S., Medal,L., Sadatsafavi,H.

Keywords:
Linear scheduling method, linear scheduling software, performance measurement framework, visualization, benefit-cost analysis

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Abstract:
The Washington State Ferry System Triangle Route (Fauntleroy – Vashon – Southworth) is heavily used and experiences a number of significant operational challenges. This report documents the outcome of a project tasked with examining different concepts of operation that would improve the performance of the Triangle Route, with a specific focus on the Fauntleroy terminal during periods of peak use. Each concept of operation describes operational procedures designed to improve the speed and efficiency of the terminal’s operations, the vessels’ load factor, the vessels’ on-time performance during peak travel periods, and if possible, the peak period capacity of the route. A variety of recommendations are made for consideration by Washington State Ferries for projects that might improve both the overall operational performance of the route and customers\' overall satisfaction with their experiences when using the route.

Authors:
Hallenbeck,M.E., Scott,E.

Keywords:
Ferry system, ferry operations, ferry revenue collection

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Abstract:
This research focused on using connected vehicle information to identify locations prone to conflicts between motorized and nonmotorized users to improve traffic safety on multimodal roadway networks. With this information in hand, transportation system users can be alerted of potential conflicts they may be involved in, before their occurrence, allowing these users to take preventive actions by making evasive maneuvers. A comprehensive review of the literature investigated existing connected vehicle (CV) and vehicle-to-X (V2X) safety applications. The methods to allow a sensor to communicate via both dedicated short range communications (DSRC) and via Bluetooth, WiFi, or another communication protocol commonly used by mobile devices were also investigated, as well as existing surrogate safety measures and their use in conflict- and safety-prediction algorithms. The review indicated that several studies have focused on the safety and operational benefits of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications; however, the safety benefits of V2X communications have not been sufficiently explored. In this project, a cost-effective, solar-energy driven, small, and lightweight communication node device, called the Smart Road Sticker (SRS), was developed to enable communications between connected vehicles and other roadway users via protocols such as LoRa and Bluetooth, and potentially DSRC. A supporting mobile application that allows pedestrians, bicyclists, and drivers of unconnected vehicles to communicate with the SRS device and vice versa was also designed. A crash risk prediction algorithm, with applications for vehicle/non-motorized user crashes, was developed to identify unsafe conditions and determine appropriate CV-based safety countermeasures for system users. Next, a connected vehicle simulation test bed was established in VISSIM to evaluate the safety benefits of the proposed methodology under various traffic and landscape conditions. The findings of this study were that the number of conflicts increased when the penetration of connected devices decreased. In addition, increasing the traffic volume had a direct relationship with increasing the number of conflicts. Finally, a real-world test bed was established for installation of sensors, data collection, and analysis, as well as to initiate further smart cities research within the state.

Authors:
Wang,Y., Ash,J., Zhuang,Y., Zhibin,L., Zeng,Z., Hajbabaie,A., Hajibabai,L., Tajalli,M.

Keywords:
Safe traffic operations, connected vehicles, communications node device, mobile applications, crash risk prediction algorithm, simulation test bed

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Abstract:
Within the Seattle metropolitan area, traffic incident management (TIM) operations provide a multi-jurisdictional and coordinated strategy to detect, respond to, and clear traffic incidents so that traffic flow can be restored quickly and safely. There is a need to extend TIM to include congestion management (CM), a complex activity for managing incident-generated congestion and for mitigating regional impacts after the actual incident has been cleared. This project identified challenges and opportunities for the enhancement of regional TIM to incorporate CM processes and operational coordination, supported by innovative technologies. The researchers engaged regional stakeholders in a series of iterative scoping and participatory design activities to identify and articulate desired enhancements to the regional management of major incidents on the Seattle I-5 corridor. These activities were used to identify TIM and CM stakeholders, identify and review relevant policy, work with stakeholders to model the “as-is” TIM and CM processes and procedures, use the as-is model to facilitate stakeholders in identifying current pain points and opportunities for system enhancement, and articulate desired interventions made possible by innovative applications of emerging technology. The report includes recommendations for enhancing regional TIM to incorporate CM and a five-stage approach for conducting Phase 2 of this research.

Authors:
Haselkorn, M., Yancey, S., Savelli, S.

Keywords:
Congestion management systems, Traffic incident management, Transportation management

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Abstract:
This report aims to supplement our previous report (Yonge et al. 2016; WA-RD 816.3) that assessed copper and zinc adsorption to lignocellulosic filtration media using laboratory tests and field-scale column tests for urban stormwater remediation. The current project extends the species of wood materials that were investigated in the earlier study. We performed laboratory tests using Douglas-fir crumbles®, poplar crumbles®, tanoak crumbles®, lodgepole pine crumbles®, Ultra-char of poplar®, Ultra-char of alder®, and Ultra-char of Douglas-fir® to evaluate their ability to adsorb copper and zinc. The laboratory column test results indicated that the most efficient adsorption medium for both copper and zinc is ultra-char of poplar, followed by tanoak crumbles, poplar crumbles, ultra-char of Douglas-fir, Douglas-fir crumbles, lodgepole pine crumbles, and ultra-char of alder, in that order. However, the batch experiments showed that tanoak is the most efficient adsorption medium of the samples tested. Based on the summary results of both the column and batch experiments, among all the samples of wood crumbles and char, tanoak crumbles seem to be a better option for metal adsorption. One of the most important conclusions drawn from this project is that the surface areas of both wood crumbles and ultra-chars of different wood crumbles are highly relevant to their ability to adsorb copper and zinc. Building on our previous research, we found that surface area is a critical parameter for copper and zinc removal, and the role of functional groups is not as important as we had expected. Typically, chars have larger surface areas and fewer functional groups than wood crumbles. The presence of functional groups would favor metal adsorption when two materials share similar surface areas, which may explain the superior adsorption performance of raw wood crumbles over char that we reported in our previous report (Yonge et al. 2016).

Authors:
Chowdhury, I., Tian, Y., Shams, M., Wolcott, M., Dooley, J.

Keywords:
Stormwater, ferry terminals, filtration, copper, zinc, Washington State

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Abstract:
In bridges constructed with precast prestressed concrete girders, resistance to seismic effects is achieved by the interaction between the columns, the cap beam and the girders. These components must be connected to provide flexural resistance. Under the impact of longitudinal seismic motion, the bottom flanges of the two girders that meet end-to-end at the cap beam will be under tension and compression, respectively. The tension connection between bottom girder flange and cap beam is presently made by extending some of the bottom strands into the cast-in-place diaphragm. At this location, the space available is too small for development by bond in the straight strands alone, so some form of mechanical anchorage is needed. Since concrete in the diaphragm is highly confined, it can probably carry high bearing stress and an anchor with a small bearing area may be possible. Thus, the goal of this project is to create a reliable, effective, as well as practically applicable, way of anchoring strands extended from the girder into the cap beam. The first stage in the development of the girder-diaphragm seismic connection consists of establishing the adequacy of the smallest possible strand anchor that still leads to a strand ductile failure due to yielding rather than strand anchor failure by crushing of the concrete. As a second stage, the impact of the possible failure mechanisms of the strands, embedded in the diaphragm, on the development of the girder-cap beam positive moment connection was investigated. Finally, the distribution of girder bending moments across the bridge deck was evaluated, while investigating the influence on that distribution of the most important bridge parameters, such as cracking of bridge components, as well as varying cross sectional dimensions.

Authors:
Tsvetanova, K., Stanton, J.F., Eberhard, M.O.

Keywords:
Longitudinal seismic resistance, Positive moment, Extended girder strands, Girder-cap beam connection, Precast prestressed concrete girders, Strand anchorage bearing capacity

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Abstract:
This research report presents an improved process for evaluating the benefits and economic tradeoffs associated with a variety of highway preservation projects. It includes a summary of results from a comprehensive phone survey concerning the use and application of the software developed by the Federal Highway Administration (FHWA), known as the Highway Economic Requirement System (HERS-ST). This national survey revealed that only a few states utilize this software in evaluating highway preservation projects and revealed an existing need to bridge pavement management and economic impact analyses in the evaluation of highway preservation projects. This research project developed a supplemental software application tool within Excel to improve the HERS-ST software and enhance the capabilities of evaluating highway preservation project analyses. This software application, the HERS-ST Benefit Application Tool (HERS-ST-BAT), has been developed to enhance and improve upon the project evaluation process. By combining HERS-ST-BAT and HERS-ST, the analyst is able to provide estimates for a variety of regional- level agency and user costs associated with preservation programs and more effectively consider different investment alternatives. Three separate preservation project case studies are selected to apply the HERS-ST- BAT and detailed results presented.

Authors:
Jessup, E.L., Zhou, Y., Lang, E.

Keywords:
Highway preservation, economic analysis, user benefits

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Abstract:
Transit agencies identify two types of exposure to crime: the safety of riders and security. Transit operators have long monitored crime and are cognizant of high incident locations. However, they lack data-driven tools to readily match crime events spatially with the locations of individual transit facilities, and temporally with transit service periods. This pilot project explored the use of data-driven tools to (1) identify concentrations of criminal activity near transit facilities, and (2) assist decision-making regarding the selection of countermeasures and the allocation of future safety investments, using the results of models estimating environmental and socioeconomic predictors of crime near transit facilities. The project used two novel data sets: location-specific, police-reported crime incidents by type; and individual ORCA card (electronic transit fare payment system) transaction records, yielding transit ridership data. Two sets of models were developed to examine exposure to crime while waiting for transit (within 100 m from transit stops) and while walking to transit (within 400 m from transit stops). The hypotheses were that within 100 m of a stop, amenities at stops act as deterrents of crime; and within 400 m different characteristics of the built, social, and transportation environment are associated with crime. Analyses were restricted to the City of Seattle, and models were run using all stops and only stops located in the City’s urban villages (hosting 90 percent of the City’s ridership and the stops with the most crime). We found that amenities at stops have mixed associations with crime, suggesting that amenities serve to provide riders with added comfort but not necessarily more safety. Higher ridership provides safety while waiting for transit (100-m models) but exposes riders to more crime as they walk to and from transit (400-m models). In urban villages, sidewalks are associated with a lower likelihood of crime. However, a more connected street network, which characterizes the oldest, most urban areas of Seattle, is associated with more crime. The project illustrated how novel sets of disaggregated data on both crime and transit ridership can serve to develop models assessing the safety of transit riders at specific locations. Future research should continue to examine how transit riders can be protected from crime while they wait for transit as well as while they walk to and from it.

Authors:
Moudon, A.V., Bassok, A., Kang, M.

Keywords:
Transit stop amenities, Transit neighborhood, Disaggregate, Crime data, Transit transaction data

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Abstract:
Under the Dynamic Mobility Applications (DMA) Program, the U.S. Department of Transportation (U.S. DOT) has sponsored the development of the Freight Advanced Traveler Information System (FRATIS) bundle, which seeks to transform freight mobility by leveraging a system of “connected vehicles” and mobile devices to maximize freight flow. The TxDOT I-35 Traveler Information During Construction (TIDC) system has been enhanced to help maximize freight operators’ productivity, improve operational efficiency, and reduce safety related incidents, by providing freight traveler information such as pre-construction closure notifications, delay predictions, and near real-time construction delay information. The report evaluates the benefits of the delivery of the TIDC’s information to the trucking firms using the system. It is based on a year-long before/after analysis of two major trucking firms, with six months of data collected before the firms started using TIDC information, and six months of after data collection after TIDC information started being used by the companies. At the conclusion of the project, both participating trucking firms remain enthusiastic supporters of the TIDC and are seeking internal company resources for improving the ability of their companies to ingest TIDC data into their existing business processes, however, no quantifiable change in trucking performance was observed. Reasons for the lack of measurable benefit include the limited opportunity to route around the I-35 construction delays, and the lack of automated ingest of TIDC data into the trucking firms’ business systems.

Authors:
Hallenbeck, M.E., McCormack, E.D., Zyuzin, D., Ishimaru, J., Jensen, M., Campbell, R., Chu, A.

Keywords:
Freight advanced traveler information, FRATIS, traveler information, during construction, TIDC, I-35, Texas, before/after analysis

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Abstract:
The performance and impacts of several agro-based anti-icers along with a traditional chloride-based anti-icer (salt brine) were evaluated. A statistical design of experiments (central composite design) was employed for developing anti-icing liquids consisting of cost-competitive chemicals such as agro-based compounds (e.g., Concord grape extract and glycerin), sodium chloride, sodium metasilicate, and sodium formate. The following experimentally obtained parameters were examined as a function of the formulation design: ice-melting capacity at 25°F (−3.9°C), splitting strength of Portland cement mortar samples after 10 freeze-thaw/deicer cycles, corrosion rate of C1010 carbon steel after 24-hour immersion, and impact on asphalt binder stiffness and m-value. One viable formula (“best performer”) was tested for thermal properties by measuring its differential scanning calorimetry (DSC) thermograms, the friction coefficient of asphalt pavement treated by this anti-icing formulation (vs. 23 wt.% NaCl and beet juice blend) at 25°F after being applied at 30 gallons per lane mile (1 hour after simulated trafficking and plowing), and other properties (pH, oxygen demand in COD). Laboratory data shed light on the selection and formulation of innovative agro-based snow-and ice-control chemicals that can significantly reduce the costs of winter maintenance operations.

Authors:
Shi, X., Nazari, M.H., Oh, T, Ewing, A.C., Okon, D.A., Zhang, Y., Avalos, B., Alnuaimi, E., Havens, E.A.

Keywords:
Agro-based anti-icer, ice-melting performance, Portland cement mortar, splitting strength, asphalt binder, stiffness, m-value, corrosivity, DSC, friction coefficient, COD

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Abstract:
With the explosion of the number of studies using big, passively-generated data for transportation analysis, this study focuses on understanding the properties of such data and how these properties affect our ability in deriving trip-related characteristics. Two big data sets were analyzed: a mobile phone data generated primarily on phone calls with locations identified through cellular triangulation and an app-based data generated primarily on app usage with locations identified through a mix of positioning technologies including GPS and cellular triangulation. Both data sets were compared against their household travel survey counterparts. It is shown that the two data sets, generated through different positioning technologies and usage mechanisms clearly have different spatial and temporal characteristics, which then affect trip related attributes such as trip rates and OD patterns. Implications in planning applications and future work are discussed.

Authors:
Ban,X., Chen,C., Wang,F., Wang,J., Zhang,Y.

Keywords:
Big data, mobile phone data, app-based data, travel surveys, travel patterns, origin-destination demand matrices

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Abstract:
Concrete-filled steel tubes (CFSTs) and reinforced concrete-filled steel tubes (RCFSTs) are increasingly used in transportation structures as piers, piles, caissons or other foundation components. While the axial and flexural properties of CFTs have been well researched, research on their shear resistance is lacking. Currently accepted methods for calculating the shear capacity of CFSTs and RCFTs are adapted from shear strength equations used for structural steel or reinforced concrete components. Though, it is expected that CFSTs would retain the full shear capacity of the steel without local buckling of the section. In addition, because circular CFSTs provide optimum confinement to the concrete core, it is also expected that the full shear strength of plain or longitudinally reinforced concrete can also be developed. Since no equation currently accounts for both, it is probable that they significantly underestimate the effectiveness of the composite section, potentially increasing undesirable conservatism and cost. However, without experimental data to validate the design expressions, it is not possible to modify them. The research program described herein experimentally investigated the shear resistance and deformation of CFST and RCFST members with an eye towards developing an improved and more accurate shear strength expression. The experimental study included 22 large-scale CFTs subjected to four-point bending. The study parameters included: (1) the aspect ratio (a/D where a is the clear span from the point of loading to the point of support and D is the tube diameter), (2) concrete strength, (3) D/t (where t is the thickness of the steel tube), (4) interface condition (greased or contaminated with soil), (5) infill type (concrete or gravel), (6) internal reinforcement ratio, and (6) length of the tube beyond the support (tail length). The results indicate that the shear strength of CFSTs and RCFSTs is on average 2 times the current WSDOT expression. This new design expression for shear resistance has been proposed for implementation in the WSDOT Bridge Design Manual (BDM).

Authors:
Roeder, C., Lehman, D., Heid, A., Maki, T.

Keywords:
concrete filled steel tubes, CFST, RCFST, shear resistance

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Abstract:
WSDOT produces and uses estimates of vehicle delay on state highways throughout the state. Large swings in delay computed on some roads and in some corridors by the current statewide delay process resulted in the decision to review the performance of that system. As a result, this project was undertaken to examine the causes of these wide swings in reported delay and to determine possible courses of action for WSDOT. The project reviewed the software used to produce those delay estimates, the input data sets used in those computations, and the steps followed to generate those data sets. This report recommends changes to the delay computation process. The report describes several different approaches that could be adopted by WSDOT to compute vehicle delay. It makes recommendations for WSDOT’s consideration. The best option is a function of the funding available to WSDOT and the other uses for the data needed to drive each of those various approaches to delay computation.

Authors:
Hallenbeck, M.E., Ishimaru, J.

Keywords:
Performance measures, Roadway performance measures

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Abstract:
As the part of the Washington State Department of Transportation (WSDOT) pile attenuation test program, researchers from the University of Washington Applied Physics Laboratory (APL-UW) conducted underwater sound measurements on 7 and 8 December 2015 at the Vashon Island ferry dock. A WSDOT team operating closer to the construction barge also took measurements. The goals of the APL-UW team were to measure the underwater sound field over nearly the entire water column and away from interfering structures, as well as to make robust estimates of sound mitigation performance of two test pile designs in terms of sound exposure level (SEL) and peak pressure. Measurements on the R/V Robertson were taken at a range of 120 m from the construction barge complex and pile source location and at a water depth 12.5 m by using a vertical line array (VLA) that spanned 1.25 to 9.25 m in depth. A comparison of the 7 December measurements from the double wall test pile with the control pile showed reductions in peak pressure (8.7–13.5 dB), RMS pressure (8.8–12.7 dB), and SEL (7–10.3 dB). A comparison of the 8 December measurements from the mandrel test pile with the 7 December measurements from the control pile showed reductions in peak pressure (11.4–14 dB), RMS pressure (10.8–12.6 dB), and SEL (9.3 and 11.1 dB). The reduction in peak pressure generally increased as measurement depth on the VLA increased; for the RMS and SEL metrics, no trend was observed.

Authors:
Dahl, P.H., Dall'Osto, D.R., Laughlin, J.

Keywords:
Impact pile driving, Underwater sound, Sound mitigation, Attenuation, Sound exposure level (SEL),

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Abstract:
Sandy soil layers reduce in volume during and following liquefaction. The downward relative movement of the overlying soil layers around drilled shafts induces shear stress along the shaft and changes the axial load distribution. Depending on the site conditions, the change in the axial responses that result from liquefaction-induced settlement and the drag load can have a significant impact on the performance of drilled shafts in seismic regions. This study presents an analytical method to quantify the effects of liquefaction-induced downdrag on drilled shafts. The analytical method is based on the neutral plane method originally developed for clays but modified to account for liquefaction-induced effects. The neutral plane method is a simplification of soil-shaft interactions and is more representative of actual conditions than other methods. In this study, the neutral plane method was applied to an observed case of downdrag during the 8.8 magnitude earthquake in Maule, Chile, and was able to predict the liquefaction-induced settlement that was the major cause of failure of the structure. The developed procedure is illustrated for two field cases of drilled shafts in liquefiable soils in Washington state.

Authors:
Muhunthan, B., Vijayathasan, N.V., Abbasi, B.

Keywords:
Axial loads, liquefaction-induced settlement, sand, seismic analysis, side resistance, soil liquefaction, soil settlement, drilled shafts

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Abstract:
Pervious concrete pavements are permeable pavement systems that are desired for their role in stormwater management and runoff control. Increased popularity in pervious concrete pavement applications has increased the need for the development of quality control and quality-evaluation test procedures that are better suited to pervious concrete than to traditional concrete. This brief study took a few preliminary steps in that direction by investigating the effects of specimen size on the physical properties of pervious concrete, such as hardened porosity and density, as well as compressive strength. Moreover, the study investigated the effects of four different curing regimens combined with air and moist curing over a four-week period on the 28-day compressive strength for two specimen sizes.

Authors:
Nassiri, S., Rangelov, M., Chen, Z.

Keywords:
Pervious concrete, porosity, infiltration, compressive strength, curing

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Abstract:
This project contributes to the Washington State Strategic Highway Safety Plan, whose goals are to achieve zero road fatality and serious injury by 2030 and to reduce the number of pedestrians and bicyclists involved in motor-vehicle collisions on state highways. The study focused on “main street highways” (MSHs), which are stretches of State Routes that also act as main streets for the local populations. This report covers Part I of this study, which collected an inventory of collision data in Washington state from 2001 to 2012. The project tallied those collisions that had been geocoded, and the report describes the various methods used for geocoding. More than 90 percent of the collisions had been geocoded for 2010, 2011, and 2012, but only pedestrian and bicyclist collisions had been geocoded for the years between 2001 and 2009.

Authors:
Moudon, A.V., Kang, M.

Keywords:
Washington state collisions inventory, Inventory of geocoded collisions , Geocoding methods

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Abstract:
This project contributes to the Washington State Strategic Highway Safety Plan, whose goals are to achieve zero road fatality and serious injury by 2030 and to reduce the number of pedestrians and bicyclists involved in motor-vehicle collisions on state highways. The study focused on “main street highways” (MSHs), which are stretches of State Routes that also act as main streets for the local populations. This report covers Part II of the study, which (1) identified hotspots of pedestrian and bicyclist collisions, and (2) developed models for estimating socio-economic and environmental predictors of collision locations. Collision hotspots were derived from Planar and novel Network Kernel Density Estimation (KDE) methods. Case-control and negative binomial models showed that high risk pedestrian and bicyclist collision locations were significantly associated with collisions occurring (1) at street and road intersections (versus mid-blocks); (2) on wider roads; (3) on roads with bicycle lanes; (4) in low income and non-white neighborhoods.

Authors:
Moudon, A.V., Kang, M.

Keywords:
Pedestrian safety, Bicyclist safety, Hotspot detection , Collision risk at intersections, Built environment, Geographic information system

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Abstract:
This report documents the initial phase of a project that developed, tested, and used a methodology and tool set for converting electronic transit agency fare card transaction data, the Puget Sound region’s ORCA electronic fare card, into information that describes how customers are using the transit system. The project used two nine week datasets. The first covers February 17, 2015, to April 14, 2015. The second covers from March 26, 2016, to May 27, 2016. The report describes the detailed steps necessary to combine ORCA transaction data with vehicle location data and other data sources in order to estimate ridership patterns and other information useful for transit planning and operational needs. Data provided includes origin/destination matrices by day-of-week, and time-of-day, transfer locations, and transfer details such as the distances walked in order to transfer and the time required to make those transfers. The detailed data processing flow is described. Also included is a detailed discussion of data privacy concerns, how those concerns were addressed in this project, and how they might be addressed as part of an ongoing business intelligence system. The report also illustrates a wide variety of uses for these types of data.

Authors:
Hallenbeck, M.E., Howard, E., Zyuzin, D., Avery, R., Verma, M.

Keywords:
Electronic transit fare card data, transit planning data

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Abstract:
Shotcrete has become attractive and holds potential to replace cast-in-place (CIP) concrete for elements like retaining walls and slope stabilization. However, this practice is still limited due to concerns of drying shrinkage cracking, long-term durability, and debonding from reinforcing bars or existing structures. To provide best practices of shotcrete for wall fascia and slope stabilization, a comprehensive review on the state of knowledge of shotcrete is first provided. A desirable shotcrete mixture and a CIP concrete mixture from WSDOT benchmarks are tested for their basic mechanical properties, early age shrinkage, and long-term durability performance. The restrained ring test procedures adopted from AASHTO T334 are identified to be capable of evaluating early- age shrinkage cracking tendency of shotcrete, and the fracture energy test procedures based on three-point bending beam are considered to be more sensitive than the dynamic modulus of elasticity test in screening degradation effect of materials under rapidly repeated freezing and thawing action. Prolonged watering provide best practices to mitigate shrinkage cracking. In comparison with CIP concrete, the “before shooting” shotcrete mixture studied in Phase I exhibits better early age shrinkage resistance as well as long-term freeze-thaw resistance. The Phase II study will be conducted for evaluating “after shooting” shotcrete and their early age shrinkage and long term durability performance.

Authors:
Qiao,P., Zhou,Z.

Keywords:
Shotcrete, CIP concrete, prolonged watering, free shrinkage, restrained shrinkage, freeze-thaw, durability, dynamic modulus, fracture energy

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Abstract:
The Washington State Department of Transportation (WSDOT) is one of the nation’s leaders in calculating and using reliability statistics for urban freeways. The Department currently uses reliability measures for decision making for urban freeways—where it has applicable data—and as input to analyses that are part of major investment studies and other project identification and prioritization studies. The project documented in this report is intended to provide WSDOT with an online data analytics system that is capable of producing a variety of roadway performance measures specifically oriented toward identifying bottlenecks, and of determining the size, timing, and scope of delays those bottlenecks impose on travelers and freight shipments. The data used to determine the size of delays are also to be accessible as inputs to tools designed to evaluate alternative strategies for improving roadway performance. The system, Digital Roadway Interactive Visualization and Evaluation Network (DRIVE Net), which continues to be developed at the STAR Lab, is designed to integrate data from multiple, siloed data sets. It is intended to create key inputs for WSDOT’s planning and project selection process, as well as supply inputs to other analytical tools used in the planning and programming processes.

Authors:
Hallenbeck, M.E., Ishimaru, J., Cui, Z., Wang, Y., Zhang, W., Hendrickson, K.

Keywords:
SHRP2, travel time reliability, roadway performance monitoring

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Abstract:
The response of piled bridge foundations to liquefaction-induced lateral soil deformation is an important design consideration in seismically active regions. Recent research and case history data suggest that three-dimensional deformation of the approach embankment can significantly influence the loads placed on the embedded foundations during a flow failure or lateral spreading event. For example, the 2010 Maule earthquake in Chile caused widespread lateral spreading in the soil surrounding the Mataquito River bridge; however, only insignificant structural damage was observed in the bridge itself. The discrepancy between the amount of soil deformation and structural damage suggests that design procedures for this load case that do not make adequate consideration for 3-D soil deformation mechanisms may lead to overly conservative and expensive design solutions. In contrast, observed lateral spreading and damage near the Llacolén bridge was more relevant and resulted in the collapse of one of the approach sections. The Llacolén bridge approaches showed less 3-D effects on both sides of the bridge and therefore larger loads on the structural components. In this project, finite element models of the Mataquito River and Llacolén bridges were created with the OpenSees computational framework to investigate possible reduction in foundation loads during lateral spreading, as implied by the observed structural damage at the example sites. These models included beam on nonlinear Winkler foundation models, dynamic effective stress models of the bridge-foundation-soil system in plane strain, and 3-D models of the bridge abutments, approach embankments, and surrounding soils. This numerical work sought to frame load reduction mechanisms in the context of a simplified analysis procedure for the lateral spreading load case. The results of the numerical models for the Mataquito and Llacolén bridges, along with a preliminary parameter study conducted with an independent set of 3-D finite element models, indicated that consideration for the 3-D geometry of the bridge site and structure may result in tangible reductions in foundation bending demands and abutment displacements in comparison to those returned by a plane strain description of the problem or simplified analysis using 1-D models. This analysis procedure was modified to better consider the findings of this work, and it is recommended for use in the design of bridge foundations subjected to lateral spreading. Finally, the report proposes an approach to estimate the reductions in abutment displacement and associated foundation bending demands for a given site geometry. The latter is based on results from a preliminary parametric study and requires further development and validation for use in practice.

Authors:
Arduino, P., McGann, C.R., Ghofrani, A.

Keywords:
Lateral spreading, deep foundations, drilled shafts, soil liquefaction, lateral loads, liquefaction-induced lateral displacements,

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Abstract:
In past decades, many state departments of transportation and the Federal Highway Administration (FHWA) have begun working with ultra-high performance concrete (UHPC), an advanced cementitious material. WSDOT has not employed UHPC in highway bridge applications, such as connection joints for precast concrete decks and girders, because of its high cost and lack of experience with it. In this study, two viable mixtures (A4 and C3) were selected from an array of trial UHPC mixtures produced with local materials (primarily local fine sand and domestic steel fiber) for extensive performance evaluation. Researchers investigated the physical and mechanical properties (including workability, compressive and tensile strength, elastic modulus, and shrinkage) of selected UHPC mixtures and their bond properties with epoxy-coated reinforcing bars. The two considered mix designs exhibited compressive strength of up to 16 ksi, direct tensile strength of 1.1 ksi, elastic modulus of 5,000 ksi, and relatively high bond strength. Shrinkage was also characterized and was found to be comparable to that of conventional concrete. On the basis of the comparisons of the two selected mixtures' material properties and bond strength, the C3 mixture outperformed the A4 mixture and was therefore recommended for use in the second phase of the project, structural-level testing and evaluation at the University of Washington.

Authors:
Qiao, P., Zhou, Z., Allena, S.

Keywords:
Ultra-high performance concrete, UHPC, connection joints, mix design, mechanical characterization, tensile behavior, pull-out behavior

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Abstract:
Pervious concrete (PC) is a pavement material that provides a porous medium to facilitate the infiltration of stormwater to the underlayers. With the increasing use of PC pavement nationwide, the mechanical properties of the material need to be established. To do so, PC specimens of two aggregate types were prepared in various porosities. Hardened porosity, compressive, and flexural strength tests were conducted for all PC specimens. The test results from this study were supplemented by results from past research studies conducted at Washington State University, as well as those from the literature to develop multi-variable linear regression models to predict strength properties for pavement thickness design. The researchers established multi-variable linear regression relationships between the PC compressive and flexural strength, hardened porosity, and mixture design parameters. Additionally, they developed a recommended thickness design database for low-traffic-volume PC pavements with different mechanical properties and under various traffic volumes and axle load configurations. The fatigue model for conventional Portland cement concrete was used to obtain the maximum allowable load repetitions for PC slabs with three different moduli of rupture. To obtain the fatigue life of PC, four traffic categories and axle loads were obtained from the American Concrete Institute’s (ACI) guide on the design of concrete parking lots. The applied stress of each axle load on PC slabs was obtained by using a previously validated finite element model. Using the applied stress and different flexural strength values of PC, the researchers generated the fatigue life of PC slabs with various thicknesses and mechanical properties. On the basis of the calculated fatigue life and the traffic volumes specified by the ACI, the researchers developed a thickness design table. The proposed thickness design table should be updated by using a fatigue model for pervious concrete.

Authors:
Nassiri, S., Al Shareedah, O.

Keywords:
Pervious concrete, porosity, compressive strength, flexural strength, pavement design, pavement thickness

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Abstract:
In recent decades, many state DOTs have implemented ultra-high performance concrete (UHPC) in bridge construction because of its mechanical properties are advanced beyond those of conventional concrete. The Federal Highway Administration (FHWA) has extensively tested a proprietary class of UHPC, but WSDOT has been hesitant to adopt this mix because of its high cost and associated high risk. In this study, a mix design developed by Washington State University was tested for its structural performance when used in a reinforced spliced connection between adjacent concrete deck-bulb tee (DBT) bridge decks. The important parameters for this application are the bond strength of epoxy-coated reinforcing bars to the UHPC, as well as the tension strength of the UHPC when the rebar in the connection is stressed axially in tension. ASTM-standard test procedures in this study showed that compressive strengths of up to 16 ksi, tension strengths of above 2 ksi, and bond strengths of up to 7 ksi can be achieved with this particular UHPC, all with improved ductility beyond that of conventional concrete, largely because of the steel fiber reinforcements. Structural experiments were performed on idealized “bond curbs” as well as a section of deck representing actual DBT girders to determine the available bond strength and the corresponding required joint width. These experiments and the subsequent analysis showed that a UHPC joint width of 7.11 inches, corresponding to a splice length of 5.11 inches, is satisfactory to fracture the reinforcement within the connection. To account for construction tolerances, this joint width should, in practice, be increased to 10 inches.

Authors:
Peruchini, T.J., Stanton, J., Calvi, P.

Keywords:
Ultra-high performance concrete (UHPC), longitudinal joints, mechanical characterization, tensile behavior, bond behavior, deck bulb tees

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Abstract:
The response of piled bridge foundations to liquefaction-induced lateral soil deformation is an important design consideration in seismically active regions. Recent research and case history data suggest that three-dimensional deformation of the approach embankment can significantly influence the loads placed on the embedded foundations during a flow failure or lateral spreading event. For example, the 2010 Maule earthquake in Chile caused widespread lateral spreading in the soil surrounding the Mataquito River bridge, however, only insignificant structural damage was observed in the bridge itself. The discrepancy between the amount of soil deformation and structural damage suggests that design procedures for this load case that do not make adequate consideration for 3D soil deformation mechanisms may lead to overly conservative and expensive design solutions. In contrast, observed lateral spreading and damage near the Llacolén bridge was more relevant and resulted in the collapse of one of the approach sections. The Llacolén bridge approaches show lesser 3D effects on both sides of the bridge and therefore larger loads on the structural components. In this work, finite element models of the Mataquito River and Llacolén bridges are created using the OpenSees computational framework to investigate possible reduction in foundation loads during lateral spreading implied by the observed structural damage at the sites. These models include beam on nonlinear Winkler foundation models, dynamic effective stress models of the bridge-foundation-soil system in plane strain, and 3D models of the bridge abutments, approach embankments, and surrounding soils. This numerical work seeks to frame load reduction mechanisms in the context of a simplified analysis procedure for the lateral spreading load case. The results of the numerical models for the Mataquito and Llacolén bridges, along with a preliminary parameter study conducted using an independent set of 3D finite element models, indicate that consideration for the 3D geometry of the bridge site and structure may result in tangible reductions in foundation bending demands and abutment displacements compared to those returned by a plane strain description of the problem or simplified analysis using 1D models. This analysis procedure is modified to better consider the findings of this work and it is recommended to use in the design of bridge foundations subjected to lateral spreading. Finally, an approach is proposed to estimate the reductions in abutment displacement and associated foundation bending demands for a given site geometry. The latter is based on results from a preliminary parametric study and would require further development and validation to use in practice.

Authors:
Arduino, P., McGann, C., Ghofrani, A.

Keywords:
Lateral spreading, deep foundations, drilled shafts, soil liquefaction, lateral loads, liquefaction-induced lateral displacement

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Abstract:
This report summarizes the work completed under the SHRP2 (Strategic Highway Research Program 2) Local Freight Data program. Supply chain firm interviews and truck counts were conducted to better understand the Food Distribution System in the Puget Sound area. Interviews explored key business challenges, operations, and potential responses to natural gas incentives. Truck counts were conducted at grocery stores, and observations included truck type, time of day, stop duration, and parking behavior. The report includes a description of truck activity at grocery stores, and a summary of industry responses to natural gas incentives. The research contributes to the design of future freight data collection and to the development of policy responsive freight models.

Authors:
Goodchild, A.V., Ukrainczyk, L.

Keywords:
Food distribution, freight data collection, truck trip generation, natural gas, Washington state, freight models

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Abstract:
In August 2014, WSDOT changed the access controls for the HOT lanes on State Route (SR) 167. The lanes were initially designed and implemented to allow access at only six points northbound and four points southbound. Since August 23, 2014, free access has been allowed into and out of the HOT lane. This study was performed to determine the effects of allowing continuous access to the SR 167 HOT lanes. It examined customer attitudes toward the new access rules, the performance of the corridor, including both the HOT lanes and the parallel general purpose (GP) lanes, and the volumes of use and travel times experienced. It also examined the amount of revenue collected, the amount of toll evasion occurring, collision frequency and severity, and the impacts on transit operations. The changes in the corridor since the change in access rules have been complex. This report describes that complexity. In general, traffic volumes are increasing in the corridor. Travel times have degraded slightly in both the GP and HOT lanes in the corridor. Prices and total revenue are up in the HOT lane. Prices increased substantially during the first five months of operation of the new rules, decline somewhat after that, but remain higher than under access control rules. No statistically significant change in safety is apparent. A large fraction of the travelers in the corridor are in favor of the access rule changes, and that includes the transit agencies operating in the corridor.

Authors:
Hallenbeck,M.E., Ishimaru,J., Zyuzin,D.

Keywords:
performance measures, roadway performance measures, freight performance measures

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Abstract:
Increasing budget pressures are causing the Washington State Department of Transportation (WSDOT) to look for ways to reduce costs. WSDOT currently owns and operates illumination fixtures on state freeways and highways with annual operating costs measured in millions of dollars. Given the pressures to reduce the WSDOT budget, it is important to have a complete understanding of the means available to reduce operating and capital costs with the least negative impact on service, safety and sustainability. There are several ways that the WSDOT can reduce expenditures on illumination. One way is to use more efficient lighting technologies. A second is to operate illumination more judiciously. Another option is to install fewer luminaires, remove superfluous luminaires and consolidate luminaires. Executing these options effectively requires the WSDOT to collect additional information regarding current and near future illumination practices and technologies. A natural way in the process of revising and adapting WSDOT’s illumination standards is examining how the WSDOT standards compare to other state DOTs, utilities, cities, counties and other public entities internationally. Given the work required to revise, publish and promulgate a new illumination standard, it is advisable to examine the current state of practice in illumination standards in order to inform comprehensive updates. Toward that end, a comprehensive review of illumination design standards, LED illumination technologies and illumination control systems is useful for revising illumination standards. To address these aspects of illumination operation and design, a thorough literature review of existing illumination products, illumination control systems, and illumination spectrum technologies is conducted. This report reviewed existing public agency illumination standards domestically and internationally and outlined the difference in designing standards. An overview of existing luminaire technology performance, as well as operational and maintenance characteristics are provided. In addition, available illumination control and spectrum technologies for performance characteristics are summarized. The results of this literature review are useful for design and business case decisions regarding illumination installation, maintenance, and operation.

Authors:
Wang,Y., Zou,Y.

Keywords:
illumination design standard, LED luminaire technology, illumination control technology, illumination spectrum effectiveness

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Abstract:
Impact pile driving of steel piles in aquatic environments produces extremely high underwater sound levels. To address this problem, a double-walled pile has been developed to decrease the total noise transmitted into the water and substrate. The double-walled pile consists of two concentric steel pipe piles flexibly connected by a special driving shoe, allowing for an air gap between the two tubes. The double-walled pile is driven into the sediment by using traditional equipment that strikes the inner pile only. The air gap between the inner and outer pile and the flexible coupling prevent the radial deformation wave produced by the pile hammer from interacting with the water and the sediment. A second full-scale test of the double-walled pile technology was performed at Vashon Island, Puget Sound, Washington. A potential reduction of the peak pressure in excess of 17dB was observed for the double pile and of 16 dB for the mandrel pile. Root mean square (RMS) levels and cumulative sound exposure levels (SEL) decreased by 13 dB and 12 dB, respectively. Use of the WSDOT Geotechnical Design Manual Pile Driving Formula showed that the pile capacity of the novel piles was comparable to that of a control pile with the same outer diameter. PDA data were also collected from both the inner and outer piles of the mandrel and double piles and will be used to modify current software for predicting drivability and stresses in the piles (WEAP analysis) and for estimating load capacity after driving (CAPWAP analysis).

Authors:
Reinhall,P.G., Hampden,J., Dardis,T.

Keywords:
pile, sound, acoustic, attenuation, marine, pressure, SEL, sediment, Mach wave

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Abstract:
DRIVE Net is a region-wide, Web-based transportation decision support system that adopts digital roadway maps as the base, and provides data layers for integrating and analyzing a variety of data sources (e.g., traffic sensors, incident records). Moreover, DRIVE Net offers a platform for streamlining transportation analysis and decision making, and it serves as a practical tool for visualizing historical observations spatially and temporally. In its current implementation, DRIVE Net demonstrates the potential to be used as a standard tool for incorporating multiple data sets from different fields and as a platform for real-time decision making. In comparison with the previous version, the new DRIVE Net system is now able to handle more complex computational tasks, perform large-scale spatial processing, and support data sharing services to provide a stable and interoperable platform to process, analyze, visualize, and share transportation data. DRIVE Net’s capabilities include generating statistics for WSDOT’s Gray Notebook (GNB), including travel times, throughput productivity, and traffic delay calculations for both general purpose and HOV lanes, each of which are important performance indicators in the WSDOT congestion report. The DRIVE Net system includes robust loop detector data processing and quality control methods to address the data quality issues impacting loop detectors throughout the state. The capabilities of the DRIVE Net system have been expanded to include safety modeling, hotspot identification, and incident induced delay estimation. Specifically, the Safety Performance module includes functions that can be used to obtain traffic incident frequency, apply predictive models to estimate the safety performance of road segments, and visualize and compare observed incident counts and different predictive models. Additionally, a module providing multi-modal data analysis and visualization capabilities was developed as a pilot experiment for integration of heterogeneous data. This module includes pedestrian and bicycle, public transit, park and ride, Car2Go, and ferry data downloading and visualization. DRIVE Net now offers role-based access control, such that access privileges to different functions and data resources can be assigned on a group or individual basis. The new system is able to support more complex analytics and decision support features on a large-scale transportation network, and is expected to be of great practical use for both traffic engineers and researchers. With a modular structure and mature data integration and management framework, DRIVE Net can be expanded in the future to include a variety of additional data resources and analytical capabilities.

Authors:
Wang, Y., Zhang, W., Henrickson, K., Ke, R., Cui, Z.

Keywords:
Freeway performance measurement, WSDOT Gray Notebook, geospatial data fusion, data Quality Control, automatic pedestrian data collection

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Abstract:
As the Washington State Department of Transportation’s (WSDOT) interest in developing a statewide freight model has grown, so too has the need to better understand potential responses of major industries to different policy and market scenarios aimed at reducing freight emissions. This research seeks to understand the wheat supply system and its transportation characteristics, as well as potential behavioral responses by wheat suppliers to changes in policy and market conditions, particularly the feasibility of alternative fuel adoption. To accomplish this, the research team has conducted both new interviews within the wheat supply chain actors, as well as identified existing data sources that help broaden the picture of wheat movement. Results suggest that research is needed to better understand and develop both the power generation of alternative fuel engines as well as the logistics of fuel distribution infrastructure. This is particularly evident for rural freight networks that move heavy agricultural or natural resource based products.

Authors:
Sage, J., Casavant, K.

Keywords:
wheat supply chain, alternative fuels, freight

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Abstract:
This research examined the feasibility of using self-cleaning oil filtration systems in the Washington State Ferries (WSF) fleet from a three-pronged perspective: (1) filtration effectiveness, (2) environmental impacts, and (3) cost impacts. A pilot self-cleaning filtration system, which filters oils without using disposable filter cartridges, was installed on one vessel from which to collect data. Filtration effectiveness was analyzed by using oil analysis records and trending the values of oil properties known to be important for lubrication and which indicate oil degradation. Results showed little difference between the standard paper cartridge filtration system currently in wide use and the self-cleaning system. Environmental impacts were analyzed with a life cycle assessment methodology that quantified potential impacts on the basis of expected operation. There were fewer impacts from oil and filter use for the self-cleaning system, but the additional diesel fuel consumed by that system outweighed the benefits for most impact categories. Cost impacts were analyzed with a life cycle cost analysis, which suggested that the standard system would outperform the self-cleaning system in terms of whole life cost (unless the oil lifetime could be increased by more than three-fold), again mostly because of the the self-cleaning system's additional fuel use. Therefore, if expected costs and environmental impacts are major decision points, it appears that a suitable alternative system would need to consume less diesel fuel to be viable. However, the self-cleaning system analyzed in this report would likely decrease risks, such as oil spills during filter handling, and provide operational benefits attributable to reduced expected maintenance. The pilot system was removed following the data collection period, and deployments of self-cleaning filtration systems to other WSF vessels are not expected.

Authors:
Haselbach, L., Langfitt, Q.

Keywords:
Self-cleaning oil filtration, bypass oil filtration oil analysis, life cycle cost analysis, life cycle assessment, lubricating oil, Washington State Ferries

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Abstract:
This study identifies and evaluates hot mix asphalt (HMA) mix design and construction techniques with potential for improving WSDOT pavement surface life. WSDOT pavement failure mechanisms are found to be predominantly cracking. Rutting may reach a failure threshold first in areas with high traffic or studded tire use. A literature review, survey of state DOT practices, case study, WSPMS (Washington State Pavement Management System) data analysis, and limited laboratory testing identified 17 construction and mix design techniques with promise. Of these 17 techniques the use of stone matrix asphalt (SMA) mixtures for high-traffic interstate routes, 3/8-inch nominal maximum aggregate size mixes for medium/low traffic routes and mountain passes, non-Superpave aggregate gradation, reduced N-design gyration levels for Superpave mix design, and warm mix asphalt (WMA) to aid compaction are highly recommended for further investigation and implementation. Other techniques recommended for further investigation and possible implementation are: adoption of a cracking performance test for Superpave mix design; applying a BST within a year of paving to reduce pavement surface aging; specifying the use of Pave IR for mountain pass jobs and cold weather paving; and using steel slag aggregate in situations that call for improved friction and resistance to studded tire wear (i.e., at mountain passes).

Authors:
Wen, H., Muench, S., Chaney, S., Littleton, K., Rydholm, T.

Keywords:
Asphalt pavement, Cracking, Rutting, Climate, Studded tire wear

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Abstract:
This report documents the use of the National Performance Monitoring Research Data Set (NPMRDS) for the computation of freight performance measures on Interstate highways in Washington state. The report documents the data availability and specific data quality issues identified with NPMRDS. It then describes a recommended initial set of quality assurance tests that are needed before WSDOT begins producing freight performance measures. The report also documents the initial set of performance measures that can be produced with the NPMRDS and the specific steps required to do so. A subset of those metrics was tested using NPMRDS data, including delay and frequency of congestion to illustrate how WSDOT could use the freight performance measures. Finally, recommendations and the next steps that WSDOT needs to take are discussed.

Authors:
Hallenbeck, M.E., McCormack, E.D., Sankarakumaraswamy, S.

Keywords:
Performance measures, Roadway performance measures, Freight performance measures

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Abstract:
Impact pile driving of steel piles in marine environments produces extremely high sound levels in the water. It has been shown that current pile driving noise attenuation techniques, such as bubble curtains and cofferdams, provide limited noise reduction because significant noise is transmitted through the sediment into the water. Similarly, the effectiveness of surrounding the pile in the water with a double walled steel tube was shown in an earlier WSDOT study to be limited. To address this problem, a double walled pile has been developed to decrease the total noise transmitted into the water. The double walled pile consists of two concentric tubes connected by a special driving shoe, with an air gap between the two tubes. The double walled pile is driven into the sediment by using traditional equipment to strike the inner tube only. The air gap between the inner and outer tube prevents the radial deformation wave produced by the pile hammer from interacting with the water and the sediment. This report discusses the design of the double wall pile and presents the results from finite element modeling of the pile, scaled prototype testing, and full-scale field testing in Commencement Bay, Puget Sound, Washington. The tests showed that the double walled piles reduce the peak sound pressure over 20 dB relative to single walled piles at a range of approximately 8 meters. They also showed that, in contrast, only a 3- to 6-dB reduction is obtained when a bubble curtain is used on a full-scale, single walled pile.

Authors:
Reinhall, P.G., Dardis, T., Dahl, P.H.

Keywords:
Pile driving impact, Acoustics, Underwater noise, Attenuation, Propagation

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Abstract:
This research quantifies the changes in greenhouse gas (GHG) emissions and energy consumption from WSDOT between 1990 and 2010 associated with (1) using warm mix asphalt (WMA), reclaimed asphalt pavement (RAP), fly ash, and slag in pavement materials; (2) use of the dowel bar retrofit (DBR) as a portland cement concrete pavement (PCCP) rehabilitation practice; (3) improvements i WSDOT pavement network roughness; and (4) adoption of a long-life asphalt concrete pavement (ACP) strategy. Findings showed the following: Use of WMA, RAP, fly ash, and slag can result in GHG emissions and energy consumption savings of 4-44 percent, depending on the scenario. DBR use can save on the order of 15 percent in GHG emissions and energy consumption if it extends the life of existing PCCP by 15 years. WSDOT's overall pavement network actually got rougher from 1990 to 2010; therefore, no savings associated with GHG emissions or energy consumption were realized. Reducing WSDOT pavement network roughness as a means to reduce GHG emissions may cost on the order of $44/MTCO2e, which is quite expensive by any measure. There was no discernible trend toward long-life asphalt ACP from 1990 to 2010. Therefore, no savings associated with GHG emissions or energy consumption were identified. In context with the GHG emission and energy consumption associated with WSDOT fleet operations and vehicles driving on WSDOT pavement, total savings is on the order of 0.2 to 0.3 percent.

Authors:
Muench, S.T., Caraballo, E.M., Lin, Y.Y.

Keywords:
Greenhouse gas emissions, energy consumption, paving practices, sustainability

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Abstract:
The recently completed State Rail Plan for the state of Washington identified several key issues facing the state’s rail system. Among these key issues are abandonment, port access and competitive needs of the ports and local production regions, as well as intermodal connectivity. Nearly 2000 miles of rail line had been abandoned in Washington State before the late 1990’s, and another 70 have been abandoned since. Many of these miles included were a result of the Class I railroads stepping away from their less profitable lines. These same actions by the Class I railroads also generated opportunity for the creation of many of the state’s short-line railroads on branch and light density lines. The rail system grew smaller during the 1980s and 1990s, and many of the state short lines were not upgraded to meet the standards and conditions required for modern freight rail load limits (286,000 pounds per car). Further investment is needed should the state or owner seek new or improved operations. This study found that more than 55 percent (740 miles) of all short line miles within Washington are not able to efficiently handle 286,000 pound rail cars. Overcoming this deficiency and bringing the state’s short line system to Class II operating status could require infrastructure investments of approximately $610 million. This need exceeds the current funding support offered by the state, even if considered over a 20 year horizon with private industry and/or local jurisdictions providing significant match. Three short line case studies in this report help identify the societal benefits associated with a functioning short line system within the state’s dynamic transportation network. These case studies, along with information about the attributes that contribute to the success or failure of investments in load centers, illustrate the benefits of state investment in the short line railroad system.

Authors:
Sage, J., Casavant, K., Eustice, J.B.

Keywords:
Short line rail, Freight, Railroad

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Abstract:
Wood guardrail posts are subject to decay and deterioration, yet most DOTs have minimal or no inspection procedures in place for wood guardrail posts. The objective of this study was to identify nondestructive testing technologies to assess the condition of wood guardrail posts for internal decay. The stress wave timing (SWT) technique was judged most promising, and a prototype device was developed with an industrial partner. The prototype SWT device was validated using wood guardrail posts removed from service. Internal conditions of the posts were accurately detected in 86% of the specimens. The device also successfully detected the internal condition of all posts inspected during a field test. An inspection procedure was recommended for implementation using SWT in conjunction with drilling of posts that identified as suspected decay.

Authors:
Bender, D.A., Olszko, E.

Keywords:
Nondestructive testing (NDT), Nondestructive evaluation (NDE), Stress wave timing (SWT), wood, guardrail

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Abstract:
Compost is often used in raingardens, roadsides, and bioretention systems, not only because of its beneficial properties on soil quality, but also because compost improves water infiltration and retains stormwater contaminants. However, when compost is freshly applied, materials from compost can leach out when rain or stormwater seep through compost or compost-amended bioretention media. The goal of this research project was to experimentally evaluate and characterize leachates from compost. We quantified and characterized the leachate composition of compost following intermittent, simulated storm events. We used municipal compost of different ages and different source materials. Compost was filled into columns and then irrigated with deionized water and stormwater. Stormwater was spiked with copper to increase copper concentrations. Six-month, 24-hour rain storms were applied every two weeks for a total of up to 18 rain storms. Outflow was analyzed for pH, electrical conductivity (EC), particulate concentration, surface tension, dissolved organic carbon (DOC), nitrogen, phosphorus, and copper. Particulate and dissolved organic matter was further characterized for molecular structure by Nuclear Magnetic Resonance (NMR) and Fourier-Transformed Infrared (FTIR) Spectroscopy. Our results showed that concentrations of dissolved and particulate organic carbon and electrical conductivity in the leachate where high at the onset of each storm, but decreased as the storm progressed. However, each new storm released another peak of constituents. Leaching from mature compost was less a function of age and type, but more a function of number and frequency of storms and leaching history. Concentrations of nitrogen, phosphorus, and copper were high in the initial few storms, and then decreased. Only a small fraction (3%) of the copper present in the compost leached out, but nonetheless, the copper concentrations in the leachate remained above the regulatory waste discharge standards. NMR and FTIR analyses revealed that dissolved organic carbon consisted mainly of aliphatic and aromatic components typical of fulvic and humic acids. Our results show that municipal compost can serve as a sustained source of leaching of nutrients and metals, regardless of compost age and source. However, the copper concentrations observed in our experiment are likely not toxic due to the presence of elevated DOC, as DOC readily forms complexes with dissolved copper thereby reducing its toxicity to aquatic organisms. The DOC plays a dual role in terms of copper fate and transport: DOC can enhance leaching of copper by forming aqueous complexes, but at the same time, reduces toxicity of copper because copper-DOC complexes are less bioavailable.

Authors:
Flury, Markus, Mullane, Jessica M., Chahal, Maninder K., Cogger, Craig G.

Keywords:
Compost, Leaching, Nitrate, Phosphorus, Copper

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Abstract:
Because access to travel time information can significantly influence the decision making of both agencies and travelers, accurate and reliable travel time information is increasingly needed.One important step in providing that information is to identify the sensors best suited to provide travel time data for a given corridor. Currently, few studies have evaluated the effectiveness of various travel time data collection technologies side-by-side. This evaluation was intended to provide decision support for transportation agencies looking to select travel time systems on the basis of accuracy, reliability, and cost. This study focused on two test corridors: State Route 522 (SR 522) (an urban arterial with frequent intersections) between the NE 153rd Street and 83rd Place NE intersections, and I-90 (rural freeway built over Snoqualmie Pass in the Cascade mountains) from milepost 109 (Ellensburg, Wash.) to milepost 32 (North Bend, Wash). The sensor systems tested were Washington State Department of Transportation’s pre-existing automatic license plate reader (ALPR) system, Sensys emplacements, the TrafficCast BlueTOAD system, Blip Systems BlipTrack sensors, and a third-party feed from Inrix. This study’s approach was to look at the Mean Absolute Deviation (MAD) to judge the expected magnitude of error, then examine the Mean Percent Error (MPE) to find ant systematic biases in the data. The Mean Absolute Percent Error (MAPE) was useful for finding the relative magnitude of the error, and the Root Mean Square Error (RMSE) was used to determine whether a few large errors or many smaller errors were occurring. Each system in the analysis demonstrated different strengths and weaknesses that should be considered in addition to its accuracy and sample rates. Some systems can provide additional data; others trade accuracy and coverage for cost or portability. Ultimately, engineers will need to weigh their requirements for accuracy and sample rates against the other engineering constraints imposed on their system.

Authors:
Cheng, T., Malinovskiy, A.Y., Corey, J., Namaki, B., Wang, Y.

Keywords:
accident rates

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Abstract:
The mission of the Washington State Department of Transportation (WSDOT) is to keep people and business moving by operating and improving the state’s transportation systems vital to our taxpayers and co mmunities. Traditionally, the Department has focused its efforts on the transportation systems. However, a growing portfolio of transportation assets is burdening an old and often outdated portfolio of building assets that support WSDOT core mission and ho use employees, who design, construct, maintain, and operate state highways. The capacity and condition of these building assets are critical ly challenged by the failure of various building systems, which, when they happen, can be very disruptive or even ha zardous to WSDOT daily operations. Considering the long overdue preservation and replacement of these assets, there is an urgent need to (1) understand how the asset performance influences the various functions that support the Department’s core mission, ( 2) identify the impact of alternative funding levels upon building asset performance, and (3) prioritize the Department’s fundin g decisions in order to fulfill its core mission through a safe and sustainable working environment. This research project is th e first step in a series of potential research projects designed to develop an in - depth understanding of building asset management processes, challenges, and opportunities for WSDOT. This project is an exploratory case study focusing on the Vehicle Repair Shop in the Northwest Region Maintenance Facility in South Seattle. This shop was built in 1954 and is located in a site complex with 33 separate structures, totaling 114,025 SF of space that houses staff and equipment for the maintenance and operation of state highways. The analysis outcomes show that failures occurring at the TEF shop can significantly affect its ability to service the department’s vehicles and equipment. Given the importance of some of these vehicle and equipment in operating the state’s transportation system, failures at the TEF shop can also significantly affect WSDOT's ability to fulfill its mission.

Authors:
El-Anwar, O., Migliaccio, G., Lin, K-Y, Gatti, U., Medina, Y.

Keywords:
accident rates

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Abstract:
The report assesses the usefulness and effectiveness of safety and public service announcement (PSA) messages through surveys conducted in four urban areas in t he United States: Chicago, IL; Houston, TX; Orlando, FL; and Philadelphia, PA. The surveys were designed to specifically address the types of safety and PSA messages for each respective city. A total of 2 , 088 survey responses were received and analyzed . Th e report further captures findings and recommendations based on the analysis of the survey responses.

Authors:
Boyle, L., Cordahi, G., Grabenstein, K., Madi, M., Miller, E., Silberman, P.

Keywords:
accident rates

Abstract:
The seismic design of pile foundations is currently performed in a relatively simple, deterministic manner. This report describes the development of a performance-based framework to create seismic designs of pile group foundations that consider all potential levels of loading and their likelihoods of occurrence in a particular area. Because of the multitude of factors that can exist at a site, development of a complete, integrated procedure that would extend from ground motions to limit state excedance was not practical. To make the problem more useful to the research sponsors, a modular approach was developed. The framework allows for the development and use of a structural model with a simplified representation of the foundation system. The discrete soil model was developed using an equivalent linear format so that stiffness and damping characteristics were consistent with deformation levels. The foundation loads computed in these analyses were then applied to a three-dimensional soil-pile group model to compute the resulting displacements and rotations of the pile cap. A computer program was developed to perform the calculations required to develop load and resistance factors and demand and capacity factors. The calculations allow a designer to select a return period for limit state excedance and then select the corresponding factors that will produce a design that corresponds to the desired limit state excedance rate.

Authors:
Kramer, S.L., Valdez, C., Blanchette, B., Baker, J.W.

Keywords:
LRFD, pile foundation, seismic design

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/827.1.pdf

Abstract:
The Washington State Department of Transportation (WSDOT) does not have sufficient pavement preservation funding to keep up with inflation and pavement needs. This has cause WSDOT to emphasize in its preservation program lower-cost options such as chip seals. The study was conducted on several aspects of WSDOT chip seals including (1) the optimum timing for alternating chip seals (or Bituminous Surface Treatment (BSTs)) with hot mix asphalt (HMA) overlays, (2) design of chip seal application rates, and (3) a range of construction and performance factors. The research incorporated surveys, literature reviews, and five BST meetings that were held between 2006 and 2011. All of these activities are summarized in this report. WSDOT has continuously changed both policy and specifications as new information became available for improving their chip seal performance. In recent years, a policy change resulted in using chip seals on roadways with up to 10,000 ADT. As such, a secondary factor examined in this study was maximum ADT levels which provide for sensible chip seal construction.

Authors:
Mahoney, J.P., Slater, M., Keifenheim, C., Uhlmeyer, J., Moomaw, T., Willoughby, K.

Keywords:
chip seals, asphalt, ADT, BST, pavement, HMA, inflation, preservation

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Abstract:
This report discusses the travel costs associated with the closure of roads in the greater Centralia/Chehalis, Washington, region due to 100-year flood conditions starting on the Chehalis River. The costs were computed for roadway closures on I-5, US 12, and SR 6, and are based on estimated road closure durations supplied by WSDOT. The computed costs are only those directly related to travel that would otherwise have occurred on the roads affected by the flooding closures. The computed costs do not include the economic losses associated with delayed delivery of goods or services, losses in economic activity attributable to travelers being unable to reach their intended destinations, or economic losses associated with the loss of goods because they could not be delivered. The reported costs do include the added costs of time and vehicle mileage associated with available detour routes. Costs were also estimated for each trip that will be abandoned. That is, this study estimated the number of trips that will not be made as a result of road closures. The researchers also conducted a sensitivity analysis of the findings for the I-5 cost computation. Sensitivity tests were conducted for the value of time, the speeds and level of congestion assumed to occur on the routes used for detours, the values associated with trips that are not made via the expected detours, the percentage of personal trips made for work/business purposes versus those being made for personal reasons, the fraction of cars and trucks willing to detour, the effects of flood closure during the weekend or the summer, and growth in traffic volumes on I-5.

Authors:
Hallenbeck, M.E., Goodchild, A., Drescher, J.

Keywords:
Road closure impacts, Flooding traffic impacts, Detour costs

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Abstract:
This project tested the prototype software and procedures being developed in conjunction with the SHRP2 L08 project, called FREEVAL-ATDM, for estimating the benefits of improved operations to freeway reliability. That software, a version of the FREEVAL software, computes performance metrics by using algorithms from the 2010 Highway Capacity Manual and new software tools. This report describes the outcome of tests of the use of that software to estimate performance of I-5 in two locations: 1) northbound through Joint Base Ft. Lewis/McCord (JBLM) and 2) northbound approaching downtown Seattle starting just south of the I-405 interchange in Tukwila. The summary conclusions from these tests are that the model can produce the useful outputs for which it was intended, but it tends to under-estimate the travel times and delays actually experienced on the roadway, and it likely needs some additional calibration.

Authors:
Hallenbeck, M.E., Ishimaru, J., Wright, D.

Keywords:
ATDM analysis, traffic operations modeling, modeling roadway reliability

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Abstract:
The search for understanding of commodity flows throughout the nation and the State of Washington is a continual process. This understanding is critical at many levels of the transportation industry and to those firms and entities that provide that transportation, or regulate and invest in the needed infrastructure. These data, usually desired at the sub national level, are essential to adequate planning by state, regional and local levels as attempts continue to improve the efficiency, effectiveness and sustainability of the transportation system. State and national travel models require those data, often on a seasonal, commodity/industrial, directional, modal, etc. basis. Determining the importance of a commodity flow on a corridor level leads to the correct prioritization of investments in infrastructure as well as increasing the ability to determine quantitative impacts of congestion, regulation and bottlenecks on a transportation system or supply chain. Using the FPTI (Freight Policy Transportation Institute) developed Intercept Survey Methodology, the research team conducted a series of seasonal truck surveys at three locations on the US 395 corridor between Deer Park and the Canadian Border. Survey results aid in the identification of not only volume and commodity movements in the region, but also bottlenecks and troubled locations identified by the survey respondents.

Authors:
Sage, J., Casavant. K.

Keywords:
intercept survey, UW 395 corridor, freight

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Abstract:
The combined Washington State Department of Transportation (WSDOT) traffic sensor data and third party data are huge in volume and are highly valuable for system operations, monitoring, and analysis. The current WSDOT traffic data archive systems, however, lack the capability to integrate third party datasets and are not offering the functions needed for real-time performance monitoring, quick operational decision support, and system-wide analysis. The goal of this study was to remove the barriers in the current datasets archived by WSDOT, automate the time- consuming data quality control process, and achieve the integration and visualization of information needed to support decision making. The research findings are not only summarized in this report but are also delivered in a functioning online system named WSDOT Digital Roadway Interactive Vi sualization and Evaluation Ne twork (DRIVE Net). This WSDOT DRIVE Net system is capable of collecting, archiv ing, and quality checking traffic sensor data from all WSDOT regions and incorporating third party data, such as those from INRIX, Inc., and weather information into the analytical platform. Roadway geometric data are properly stored in an open-sourced, geospatial database and are seamlessly connected with the traditional transportation da tasets. The existing WSDOT da ta archiving and analysis systems, CD Analyst and FLOW, are successfully recode d and integrated into the WSDOT DRIVE Net system for better efficiency and consistenc y. A series of loop data quality control algorithms is automated in the backend for detecting malfunction loops and correcting them whenever possible. With the new data platform empowered by eScience transportation principles, two commonly utilized functions at WSDOT have been implemented to demonstr ated the efficiency and utility of this new system. The first is to generate WSDOT’s Gray Notebook statis tics and charts. This new function will allo w WSDOT personnel to produce the tables and figures needed for their annual and quarterly congestion reports in seconds , a significant effi ciency improvement over the months previously necessary. The other function is the Level of Service (LOS) map for highway performance assessment. This module follows the Highway Capacity Manual (HCM) 2010 procedure to produce the LOS estimate for each roadway segment every 20 seconds based on real-tim e traffic measurements. Additionally, a mobile sensing data analysis module was developed as a pilot experiment for reconstructing pedestrian trajectories using the Media Access Control addresses captured from mobile devices. Traffic engineers and researchers can directly access the WSDOT DRIVE Net system through the Internet. The system has demonstrated its ability to support more compli cated analytical and decision procedures for large-scale transportation networks.

Authors:
Wang,Y., Ma,X., Malinovskiy,Y., Corey,J., Henrickson,K.

Keywords:
accident rates

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Abstract:
Land development that is not coordinated with transportation planning can compromise the performance of Washington's state routes.  Identifying land at risk for development along state routes can provide opportunities for proactive, collaborative planning to improve access, mobility, and safety while supporting economic development.  This project, described in two parts, provides tools to help turn adverse risks of land development into opportunities to make route improvements.      In part one, systems for identifying land at risk for development were developed for the state and local levels from relevant literature and expert input.   Risk factors for land development at the state level include historic population and job growth, population and job forecasts, and traffic conditions.  Additional risk factors at the local level include regulatory constraints, critical areas, vacant and undeveloped lands, recent sales history, building permit history, and sewer and water utilities.  the local level system was applied to three case study areas.  Results generally agreed with local knowledge, yet the method offered an objective and systematic means for comparing corridors across the state fairly.      In part two, a menu of strategies for responsibly developing state routes was developed from current WSDOT practices, literature on standard approaches, and reports of novel solutions.  Strategies were classified as planning and coordination activities, non-engineering and engineering strategies, and funding/enforcement strategies.   

Authors:
Moudon, A.V., Sheikh, A., Stewart, O., Kraus, A., Hallenbeck, M. E.

Keywords:
accident rates

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Abstract:
Built environment characteristics are associated with walking, bicycling, transit use, and vehicle miles traveled (VMT). Developing built environments supportive of walking, bicycling, and transit use can help meet state VMT reduction goals. But tools are necessary to understand how changes to the built environment may translate into changes in travel. Such tools can help optimize land use and transportation investments for reduced VMT and communicate such changes to the public. This report reviews the built environment characteristics associated with travel and the tools available that utilize these built environment characteristics to estimate travel and related outcomes such as vehicle emissions and health co-benefits. Tools ranged from simple to complex, and a number of factors should be considered when applying a tool to a planning effort.

Authors:
Moudon, A. V., Stewart, O.

Keywords:
accident rates

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Abstract:
This report describes the development of geospatial sidewalk data for the King County Urban Growth Area. Prior to the development of this data set, sidewalk data in King County were limited to select jurisdictions and existed in multiple, sometimes incompatible, formats. Existing sidewalk data were collected from 30 of 40 jurisdictions and standardized to a geographic information system (GIS) data format that stores sidewalk coverage as attributes of King County street network centerlines. For each street segment, each sides was coded as full, no, or partial sidewalk coverage. An automated coding method was developed to standardize existing data when possible. Sidewalk coverage for jurisdictions with no existing sidewalk data or with data formats incompatible with automated coding were coded manually with the aid of internet mapping resources. A total of 27 jurisdictions, including unincorporated King County, were manually coded. Overall rates of agreement between automated and manual coding were 0.95, with higher rates of agreement for street segments with full and no (0.94 to 0.97) compared to partial sidewalk coverage (0.70 to 0.72).

Authors:
Moudon, A.V., Kang, B., Scully, J., Stewart, O.

Keywords:
accident rates

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Abstract:
The AASHTO LRFD, as well as other design manuals, has specifications that estimate the structural performance of a concrete mixture with regard to compressive strength, tensile strength, and deformation-related properties such as the modulus of elasticity, drying shrinkage, and creep. The Washington State Department of Transportation (WSDOT) is evaluating the performance properties of approved concrete mixtures, and verifying the measured properties and comparing them to those expected from AASHTO specifications. Factors influencing the structural behavior of concrete mixtures include the coarse aggregate source and size, paste content, water-to-cementitious ratio, and age characteristics. These factors are not integrated within AASHTO LRFD models to predict the concrete mixture’s performance. Current specifications relate most of the structural performance properties to the compressive strength, with little regard to the mixture proportions. This research was directed toward assessing the performance of the approved WSDOT concrete mixture and the sensitivity of the properties based on aggregate source and paste content. The objectives of this research were to investigate whether modifications to AASHTO LRFD specifications were required, and if so, to recommend improvements using pertinent mixture proportions. 17. KEY

Authors:
Meader, J., Janssen, D.J., Eberhard, M.O.

Keywords:
accident rates

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Abstract:
This report presents a framework to support performance monitoring for demand management related to VMT reduction. The framework consists of performance monitoring measures and a system for their collection and dissemination. The report also provides the context within which the framework would exist, and describes how it will support a wide variety of other statewide and regional needs, thus providing additional incentive for its adoption. The intent of the Framework is to not only meet the requirements of Washington state’s legislative requirement to reduce VMT per capita (RCW 47.01.440), but to do so in a way that provides WSDOT and its partner agencies with information that supports planning and programming. The report also provides an excellent framework for developing and reporting congestion-related performance measures in support of MAP-21.

Authors:
Hallenbeck,M. E., Stewart,O., Moudon,A. V.

Keywords:
accident rates

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Abstract:
WSDOT recently installed sensors on I-5 and SR 512 that greatly improved the amount and quality of traffic congestion data available in and around Tacoma and Olympia. This report examines the public’s use of WSDOT’s traveler information services providing that enhanced information to the public. It reports the results of an Internet survey that obtained the opinions of individuals who seek information on WSDOT’s traveler information website. The survey results indicated that respondents find considerable value in the traffic congestion information WSDOT provides and believe that the Department should continue to expend funding on roadway traveler information. The report also describes the range of mechanisms survey respondents used to obtain freeway congestion information and describes the ways that individuals put that information to use once they have obtained it.

Authors:
Hallenbeck,M. E., Le,Tom

Keywords:
accident rates

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Abstract:


Authors:
Hallenbeck,M. E.

Keywords:
accident rates

Abstract:
This study was conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration.  The objective of this study is to identify the key variables necessary in estimating the impact of regular washing of steel bridges on the paint and service life, recommend methods for recording data in order to most effectively estimate the benefits of bridge washing, and to develop a framework for assessing the impact of bridge washing on paint life.  A literature review was conducted to learn more about the mechanisms of corrosion.  Then a nationwide survey was sent out to state transportation agencies.  A follow-up survey was conducted in order to obtain more detailed information about certain washing programs.  It weas concluded that little information on the effects of bridge washing exist and it is only deemed beneficial based on anecdotal assumptions.  an experiment is proposed for WSDOT that will provide hard data to make a decision.

Authors:
Berman,J.W., Roeder,C., Burgdorfer,R.

Keywords:
accident rates

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Abstract:
This study is a supplement to a previous study of bridge washing practices that focused on steel superstructures.  This study examined the perceived costs and benefits of routine washing of both steel and concrete bridges, with emphasis on substructure seats and bridge decks, by exploring current practices around the U.S. A literature review was conducted in order to learn more about these elements and their failure mechanisms.  Then a nationwide survey was conducted with state DOTs around the U.S. regarding the washing practices of decks, expansion joints, and bearings.  A follow-up survey was conducted soon afterward to collect more detailed information.  A summary of the common washing practices is given in conclusion.

Authors:
Berman,J. W., Roeder,C. W., Burgdorfer,R.

Keywords:
accident rates

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Abstract:
Tests were conducted on heat-straightened and/or bent live load hanger bars used in loading bridges in the Washington State Ferry (WSF) system. Both fatigue and ultimate strength tests were conducted. The study found that when heat-straightened three times, the hanger bars have a fatigue life that exceeds their design life. The data indicated that additional heat-straightening may be possible without concern for reducing the fatigue life. The yield strength of the hanger bars was found to be unaffected by either heat-straightening or by initial bending deformations. In both cases the hanger bar yield strength exceeded nominal values. The ultimate strength was somewhat reduced by the presence of initial bending deformation.

Authors:
Berman,J. W., Chaijaroen,V.

Keywords:
accident rates

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Abstract:
Future reauthorizations of the federal transportation bill will require a comprehensive and quantitative analysis of the freight benefits of proposed freight system projects. To prioritize public investments in freight systems and to insure consideration of the contribution of freight to the overall system performance, states and regions need an improved method to analyze freight benefits associated with proposed highway and truck intermodal improvements that would lead to enhanced trade and sustainable economic growth, improved safety and environmental quality, and goods delivery in Washington State. This project develops a process to address this need by building on previous and ongoing research by some project team members with the goal of developing an agency-friendly, datasupported framework to prioritize public investments for freight systems in Washington and Oregon. The project integrates two ongoing WSDOT funded efforts: one to create methods to calculate the value of truck and truck-intermodal infrastructure projects and the other to collect truck probe data from commercial GPS devices to create a statewide Freight Performance Measures (FPM) program. This integration informs the development of a framework that allows public agencies to quantify freight investment benefits in specific areas such as major freight corridors and across borders.

Authors:
Sage, J., Casavant, K., Goodchild, A.V., McCormack, E.D., Wang, Z., McMullen, S, Holder, D.

Keywords:
freight, benefit-cost analysis, economic impact, reliability, travel time

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Abstract:
The ability to fully understand and accurately characterize freight vehicle route choices is important in helping to inform regional and state decisions. This project recommends improvements to WSDOT’s Statewide Freight GIS Network Model to more accurately characterize freight vehicle route choice. This capability, when combined with regional and sub-national commodity flow data, will be a key attribute of an effective statewide freight modeling system. To come to these recommendations, the report describes project activities undertaken, and their outcomes, including 1) a review of commercially available routing software, 2) an evaluation of the use of statewide GPS data as an input for routing analysis, and 3) the design, implementation, and evaluation of a survey of shippers, carriers, and freight forwarders within the state. The software review found that routing software assumes least cost paths while meeting user specified constraints, and it identified criteria for evaluation in the subsequent survey. The GPS data evaluation showed that significant temporal shifting occurs rather than spatial route shifting, and it revealed significant limitations in the use of GPS data for evaluating routing choices, largely because of the read rate. Among the survey results was that the first priority of shippers, carriers, and freight forwarders is to not only meet customer requirements, but to do so in the most cost-efficient way. From a latent class analysis of routing priorities, we discovered that distance-based classification best clusters similar routing behavior. The report includes recommendations for implementing this within the Statewide Freight GIS Network model.

Authors:
Rowell,M., Gagliano,A., Wang,Z., Goodchild,A., Sage,J., Jessup,E.

Keywords:
accident rates

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Abstract:
The Washington State Department of Transportation (WSDOT) frequently employs deep pile or caisson bridge foundations for its bridge structures. Deep pile and drilled shaft foundations are increasingly important for seismic design in Washington state, because of increased seismic design load demands in bridge design specifications. A common caisson is a reinforced concrete filled tube caisson. Although these types of foundation elements are common, there are few guidelines on their design. As a result, current WSDOT design methods are conservative and neglect the many benefits provided by composite action of the concrete and the steel tube, which may result in increased cost and size of the foundation. Recent research on composite concrete filled steel tubes (CFT) shows significant benefit for applications using CFT elements, in particular that CFT elements can develop more lateral resistance and greater inelastic deformation capacity with less deterioration of resistance than reinforced concrete elements of the same weight and diameter. Hence the use of this composite action permits smaller diameter and shorter caisson foundations resulting in cost savings associated with a smaller piles and drilled shafts, less material and reduced construction time and cost. This research involves consideration of the composite properties of CFT members with internal reinforcement, and this special case of internally reinforced CFT is identified as RCFT in this report. The research study used analytical tools verified using past experimental and analytical research on CFT members and foundation connections without internal reinforcement. The research included comprehensive review of past research results including experiments and analysis of CFT and RCFT elements and connections. Design models were evaluated and compared to prior test results to determine their accuracy and reliability. A comprehensive analytical study was performed to extend this prior research to current WSDOT RCFT applications. The analytical studies were calibrated to past experimental results to document their accuracy, and the analysis included development of basic design models, fiber or section based analysis, and detailed continuum based models. No experiments were included in this initial study, but observations from prior experimental research were to be used to support the work. The goals of this preliminary study were to develop initial answers to uncertainly in the design process of these components and their connections to permit the WSDOT to begin to employ the benefits of composite action for these sub-structural systems. To that end, specific design recommendations from this preliminary research study are provided. Finally, an overview of the additional research needed to further develop the deep foundation system is provided.

Authors:
Roeder,C. W., Lehman,D. E.

Keywords:
accident rates

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Abstract:
The durability of Portland cement concrete (PCC) has long been identified as a concern by transportation communities around the United States. In this study, the long-term performance of two batches of concrete incorporating either low-degradation (LD) or normal (NM) aggregates subjected to freezing and thawing conditions was experimentally studied. The freezing and thawing test method (ASTM C666) was followed to condition all the test samples. Dynamic modulus and fracture energy for both groups of concrete samples after different numbers of freeze-thaw cycles were measured through nondestructive modal and cohesive fracture tests, respectively. Due to the higher air content in LD concrete, surface scaling was less severe under frost action. Test results showed that different aggregate degradation has an important effect on the freeze-thaw resistance of the concrete and the rate of decrease in fracture energy with number of freeze-thaw cycles for the LD concrete is higher than for the NM concrete. Compared to the dynamic modulus of elasticity, the fracture energy is a more sensitive parameter for evaluating concrete degradation caused by the frost action. Thus, the degradation of aggregate in concrete can be better evaluated by the cohesive fracture test. Additional research is needed to identify an appropriate threshold for when aggregate degradation properties become a concern. Until that time, it is recommended that WSDOT maintain their current restrictions on using low-degradation aggregates in concrete.

Authors:
Qiao,P., McLean,D. I., Chen,F.

Keywords:
accident rates

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Abstract:
This study assessed the Safe Routes to School (SRTS) program in five states: Florida, Mississippi, Texas, Washington, and Wisconsin. A database of all SRTS projects announced for funding and all schools affected by these projects was developed. The database was analyzed to (1) quantify the SRTS programs’ impact in the five states and compare them to SRTS programs nationally, (2) assess the SRTS programs’ effectiveness in increasing rates of walking and bicycling to school, and (3) identify characteristics of SRTS projects associated with greater increases in walking and bicycling to school. In the five states, 569 SRTS projects were announced for funding through April 2011. These projects reached more than 1,410 schools and 781,180 children—roughly 10 percent of the PK-8 grade public school population in the five states. Engineering components were featured in most projects, and sidewalks were the most common engineering activity. Among completed SRTS projects with before and after travel data, rates of walking increased by 45 percent (from 9.8 percent to 14.2 percent), bicycling increased by 24 percent (from 2.5 percent to 3.0 percent), and all active travel to school (ATS) increased by 37 percent (from 12.9 percent to 17.6 percent). Increases in rates measured at the project level were statistically significant. Before and after travel data were only available for projects with an engineering component. Among these projects, those that affected fewer schools and students, as well as those with encouragement and education components tended to perform better. These relationships, however, were not statistically significant. The only statistically significant relationship found was a negative correlation between baseline rates of bicycling to school and increases in rates of bicycling to school, suggesting that SRTS projects may be more effective at encouraging bicycling to school where few children already do so. The results of this study offer preliminary evidence that the SRTS program is achieving one of its primary goals of increasing rates of walking and bicycling to school and that SRTS funds are delivering a return on investment. It identified some trends of more successful projects, which warrant further investigation. As more projects end, the research framework established in this study can be used to further explore these findings and refine programs that help children safely walk or bicycle to school.

Authors:
Moudon,A. V., Stewart,O.

Keywords:
accident rates

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Abstract:
Nonlinear analyses of soils, structures, and soil-structure systems offer the potential for more accurate characterization of geotechnical and structural response under strong earthquake shaking. The increasing use of advanced performance-based design and evaluation procedures will require consideration of long-return-period motions for all structures, especially in western Washington where high seismicity is a concern and long-return-period motions are likely to be strong enough to induce nonlinear, inelastic response in soil deposits and structures. Nonlinear analyses require the specification of acceleration time histories as input; this requires the analyst to identify input motions that are consistent with the ground motion hazards at the site of interest. A considerable level of research effort has been directed toward the development of procedures for selection and scaling of earthquake ground motions for the purpose of using them in nonlinear structural analysis. This research has shown that structural response of buildings can be quite sensitive to the selection and scaling of ground motions used in nonlinear analyses. While the sensitivity of bridge structures to input motion characteristics has not been studied as explicitly as that of building structures, the response of bridges is also expected to be significantly influenced by input motion characteristics. As a result, engineers have identified the need for software tools that will automate, to at least a large degree, the process of identifying suites of ground motions that are most appropriate for use in nonlinear response analyses. Along with this report, a piece of software, SigmaSpectraW, was created for WSDOT to do just that.

Authors:
Kramer,S. L., Arduino,P., Sideras,S. S.

Keywords:
accident rates

Abstract:
The Seattle multi-modal corridor data set covers the Interstate 5 freeway corridor from the King/Pierce County line in the south to approximately the City of Everett in the north. The arterial data included in the data set cover the major City of Seattle north–south arterials west of I-5 and east of Puget Sound. The specific geographic areas covered by the data are shown in figures 1 and 2. The data set contains 6 months of data, collected from May 1, 2011, to October 31, 2011.

Authors:
Hallenbeck,M. E., Wang,Y., Ishimaru,J. M., Ma,X., Richards,M., Corey,J.

Keywords:
accident rates

Abstract:
Travel time data had been very difficult to collect until recently. Current attempts at exploiting short-range communication protocols that rely on unique identifiers, primarily Bluetooth, have significantly simplified the travel time collection task. Many transportation agencies are now considering using Bluetooth travel time estimates to feed a variety of applications, such as user information systems. As Bluetooth-based travel time data collection increases in popularity, investigating the errors that are characteristic of this detection type becomes more important. A Bluetooth sensor, called the Media Access Control Address Detection (MACAD) system, was developed for travel time data collection in this study to facilitate testing system configurations and allow for future deployments. Three types of antennae and three different sensor arrangements were tested to determine the effects of these variables on travel time error. The collected travel time data were compared to license plate reader data, which, because of their relatively small detection zone for vehicle license plate recognition, were taken as the ground truth travel time. A regression model was used to investigate whether travel time error can be predicted with observable explanatory variables. Descriptive statistical analysis was also employed to evaluate the impacts of individual variables on the travel time error. The results suggested that a combination of sensors is desirable, despite the potential loss of accuracy, as the higher matching rates obtained by the system will improve sample size and reduce random error rates. Findings of this study are helpful to transportation professionals attempting to understand the errors associated with the Bluetooth-based travel time data collection technology and to configure the sensors to mitigate the errors. 17. KEY

Authors:
Wang,Y., Malinovskiy,Y., Wu,Y-J, Lee,U. K.

Keywords:
accident rates

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Abstract:
This report addresses the question: What does it take to achieve and maintain sustainable urban roadside restoration projects in Western Washington that provide for necessary roadside functions at lowest lifecycle cost? It makes recommendations under five categories: general, agency communication and process, design, construction, and maintenance. It identifies two major problems common to urban roadside: the establishment of transient encampments and intense invasive weed pressures. Urban roadside environments are extremely varied and serve many functions; therefore, the report does not recommend a single type of roadside planting or maintenance suitable for all situations. Integrated Vegetation Management is a key tool for planning and implementing urban roadside maintenance.

Authors:
Robertson,I., Smith,L.

Keywords:
accident rates

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Abstract:
The underwater noise from impact pile driving was studied by using a finite element model for the sound generation and a parabolic equation model for propagation. Results were compared with measurements taken with a vertical line array deployed during tests at the Vashon Island ferry terminal near Seattle in November 2009. Tests showed that the dominant underwater noise produced by impact driving is from the Mach wave associated with the radial expansion of the pile that propagates down the pile after impact at supersonic speed. The effectiveness of surrounding the pile in the water with a double-walled steel tube, also called a temporary noise attenuation pile (TNAP), to reduce the underwater sound caused by pile driving operations was also investigated. Tests and analysis showed that the noise attenuation capability of the TNAP was limited to approximately 10 dB because of the unconstrained propagation of Mach waves directly from the sediment into the water. 17.

Authors:
Reinhall,P. G., Dahl,P. H.

Keywords:
accident rates

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Abstract:
This report documents the results of applying a previously developed, standardized approach for evaluating intelligent transportation systems (ITS) projects to 17 ITS earmark projects. The evaluation approach was based on a questionnaire to investigate technical, management, and organizational lessons learned. The report includes an evaluation report for each of the 17 ITS projects. Each report includes a discussion of the following: · Background · Project description · System usage and benefits · Cost, operations and maintenance · Architecture and standards · Lessons learned.Most of the lessons learned in this evaluation phase were similar to those documented in previous evaluations.

Authors:
Porter,R. D., McCormack,E. D., Briglia,P. M.

Keywords:
accident rates

Abstract:
Safe Routes to School (SRTS) programs support children safely walking and biking to and from school. Each state Department of Transportation (DOT) awards federal grant money to proposal applications made by local SRTS programs. Because demand for federal SRTS funding far exceeds most states’ budgets for their program, state DOTs must carefully select the SRTS proposals that receive an award. By definition, most local program proposals that meet the federal guidelines to receive SRTS grant money will include elements that contribute to pedestrian safety. As a result, state DOTs that wish to leverage their SRTS funds are faced with the difficult task of choosing those proposals with the greatest potential to successfully increase the safety and number of children walking or biking to school. This report compares how five state DOTs – Florida, Mississippi, Texas, Washington, and Wisconsin – select the most promising SRTS proposals for funding. It reviews how the five states approach the selection process by considering grant types, SRTS plans, eligibility requirements, program distribution policies, proposal review processes, and established selection criteria. The selection processes and criteria used are reviewed to highlight examples of best practices that consider (1) the four common barriers to walking and biking to school (distance, income, parent values and parent concerns), (2) the “five E’s” commonly used to classify SRTS program elements (engineering, education, encouragement, enforcement, and evaluation), and (3) the five conceptualized stages of an SRTS program (existing conditions, planning, proposal, implementation, and assessment of outcomes). The results of this review are insights into how the five state DOTs define an effective SRTS program and how they prioritize awards for the many good SRTS program proposals they receive. Examples of effective selection practices are identified as a basis for making specific recommendations on what constitutes a promising proposal selection process that awards programs with the highest potential to increase the safety and number of children walking or biking to school. An appendix contains documentation on the original SRTS proposal selection protocols used by the five contributing state DOTs.

Authors:
Moudon,A. V., Stewart,O., Lin,L.

Keywords:
accident rates

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Abstract:
Despite the fact that travel speed and reliability on numerous segments of the high-occupancy vehicle (HOV) lanes of the central Puget Sound freeway network are not meeting the adopted state performance standard, trends suggest that HOV travel demand is expected to increase. This study was conducted to evaluate the performance of Interstate 5 HOV lanes between Federal Way and Everett, Washington, focusing on congestion; to identify congestion bottleneck segments and potential causes; and to develop a range of potential short-term (0 to 5 years) enhancements to improve HOV traffic flow at bottlenecks. A review of estimated speeds and vehicle volumes for 2007 determined that the I-5 HOV corridor as a whole does not meet the state standard during the peak travel periods in the dominant direction of traffic (inbound to Seattle from the south and north in the AM peak, outbound from Seattle in the PM peak). Eight HOV lane segments were specifically identified as bottleneck locations of heavy congestion.The report details possible causes of congestion in these areas: heavy usage of the HOV lane, roadway geometry, lane friction, merging conflicts, slow vehicles, and incidents. The report also discusses short-term options for addressing congestion at these locations: implementing general purpose on-ramp metering, implementing inside HOV on-ramp metering, moving the HOV lane endpoint approach the northbound express lane entrance, strengthening the incident response program, introducing buffer separation, reconfiguring express lane ingress/egress, introducing active traffic management, reserving HOV lanes for bus transit only, and changing the occupancy requirement from 2+ to 3+. The advantages, disadvantages, and other issues related to these options are also discussed.

Authors:
Ishimaru,J. M., Hallenbeck,M. E., Wright,D., Kang,J.

Keywords:
accident rates

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Abstract:
This project investigated the basic relationship of incidents to delay on Puget Sound area freeways. The intent was to determine the amount of delay caused by incidents and the benefits obtained from the incident response actions taken by the Washington State Department of Transportation (WSDOT). The analysis was based on data from 2006 and included all days in 2006. The study area included I-5 from SR 526 in the north to S. 320th in Federal Way in the south; all of I-90 west of milepost 19.5, which is east of Front Street in Issaquah; all of I-405; SR 167 from I-405 to SR 18; and all of SR 520. The study showed that incidents, including crashes, do not, in and of themselves, cause measurable delay. They cause delay only when the disruption they create causes functional capacity to fall below actual demand. However, the researchers calculated that the average incident that does not involve a lane closure results in 576 vehicle-minutes of delay per minute the incident is present. If the incident closes a lane, the effect of that lane closure adds 814 vehicle-minutes of delay per minute of closure. For the 2006 study year, a conservative estimate is that crashes and other traffic incidents (including disabled vehicles, debris, and other events requiring WSDOT intervention to remove hazards) cost travelers 5,300,000 vehicle-hours of delay, in addition to typical congestion delay, on the Puget Sound region’s freeway system. That is roughly 30 percent of the total delay from all causes that occurred on these roadways. Approximately 11 percent of the total delay (1,950,000 veh-hrs) was the result of reported vehicle crashes. The study also determined that crash rates increase substantially when delays caused in part by incidents occur. In fact, a simple summary of the available data indicated that crash rates essentially double in corridors slowed by unexpected incident-related queuing. Consequently, because reducing the duration of incidents results in faster clearance of incident-related queuing, it will also have a significant safety benefit, as measured in a reduced crash rate.

Authors:
Hallenbeck,M. E., Pham,C., Watkins,K.

Keywords:
accident rates

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Abstract:
The HOT lanes on SR 167 south of Seattle, Washington, are separated from their respective general purpose lanes by a double white lane line. Legal access to the HOT lanes is limited to four locations southbound and six locations northbound. This study examined the frequency with which motorists illegally cross the double white lane line, rather than waiting for one of the legal access points. The study determined the locations and operating conditions under which violations most commonly occur.The study showed that during most times of the day and along most portions of the corridor, the number of illegal entry and exit movements is negligible. However, at a small number of locations and under specific congestion conditions, violation rates can exceed 1 per minute. The worst violation location is northbound, north of the S. 180th St on-ramp, just before the end of the northbound HOT lane and after the last toll collection gantry. Violations at this location appear to be caused by the three main factors: 1) In anticipation of the lane becoming a general purpose lane in less than another 500 feet, some motorists “jump in early.” 2) This location is often the point to which the queue from the I-405 interchange ramp backs up. Violation rates increase significantly near the upstream end of any queue. 3) Many vehicles entering the freeway at the S. 180th St ramp move as directly as possible to the left lane of the freeway and then merge into the HOT lane. In congested conditions, these movements result in lane-line violations because the slow, heavy traffic allows the weave process to occur in a short distance. Under faster free flow conditions, this weave movement requires a much longer distance, resulting in vehicle merges at the intended legal locations.

Authors:
Hallenbeck,M. E., Corey,J.

Keywords:
accident rates

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Abstract:
This report provides guidance to the Washington State Department of Transportation (WSDOT) in creating, supporting and enhancing Growth and Transportation Efficiency Centers (GTECs), especially those centers located within suburban cities. The report examines the goals of the GTEC program and makes a variety of recommendations for growing the program and expanding its effectiveness in reducing peak period SOV use under a variety of different budgetary scenarios.

Authors:
Hallenbeck,M. E., Carlson,D.

Keywords:
accident rates

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Abstract:
In order to support WSDOT in development of the Washington State Freight Mobility Plan, this document presents recommendations for criteria to be used in defining the Washington state truck intermodal network. The state does not have an existing definition of the freight truck-intermodal system. To establish the criteria, this project reviewed methods used by other states, identified the facilities in Washington specified by the National Highway System, and compared these facilities to those identified by regional planning organizations. Finally, recommendations are made for criteria to use in identifying the truck intermodal network for Washington.

Authors:
Goodchild,A.

Keywords:
accident rates

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Abstract:
The Oregon Department of Transportation (ODOT) has been placing 3/4-inch nominal maximum aggregate size (NMAS) open-graded wearing courses (OGWCs) in structural layers of 2 inches or more for about 30 years. Despite this, OGWC performance in the Pacific Northwest is not well understood. This study determined the use and performance of ODOT OGWCs, with special attention given to 3/4-inch open-graded HMA (previously referred to as "F-Mix") and recommends guidelines for the future use of OGWCs. The best estimated service life of ODOT 3/4-inch open-graded HMA ranges from 14 years (<5,000 ADT) down to 7 years (>100,000 ADT), which is less than comparable dense-graded mixes. The primary mode of distress is raveling and studded tire wear. Reduced service life, uncertain and unquantified safety benefits, and a possible greater risk of early failure lead to a recommendation to discontinue use of 3/4-inch open-graded HMA in Oregon as a standard surface mix. OGWCs used elsewhere in the U.S. are not likely suited for ODOT use because of their susceptibility to studded tire wear and are not recommended for adoption. If 3/4-inch open-graded HMA does continue in use, recommendations are as follows: (1) quantify its benefits, (2) restrict its use to low traffic (<30,000 ADT), (3) re-calibrate PMS expected life to be more in line with observed historical life, and (4) require the use of a windrow pick-up machine or end-dump transfer machine when paving OGWC.

Authors:
Muench, S.T., Weiland, C., Hatfield, J., Wallace, L.K.

Keywords:
Open-graded, hot mix asphalt, pavements, pavement performance

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