Abstract:
This report documents the development of data collection methodologies that can be used to cost effectively measure truck movements along specific roadway corridors selected by transportation agencies in Washington State. The intent of this study was to design and test methodologies that could be used to measure the performance of freight mobility roadway improvement projects against benchmarks, or selected standards, that would be used both as part of the project selection process and to report on speed and volume improvements that resulted from completed freight mobility projects. One technology tested was Commercial Vehicle Information System and Networks (CVISN) electronic truck transponders, which are mounted on the windshields of approximately 20,000 trucks in Washington. By using software to link the transponder reads from sites anywhere in the state, the transponder-equipped trucks could become a travel-time probe fleet. The second technology tested involved global positioning systems (GPS) placed in volunteer trucks to collect specific truck movement data at 5-second intervals. With GPS data it was possible to understand when and where the monitored trucks experienced congestion and to generate useful performance statistics. The study found that both data collection technologies could be useful; however, the key to both technologies is whether enough instrumented vehicles pass over the roadways for which data are required. This basic condition affects whether the technologies will be effective at collecting the data required for any given benchmark project. The report also recommends the traffic data that should be collected for a benchmark program and the potential costs of using either data collection technology.

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

Keywords:
agencies, commercial vehicle, condition, congestion, construction, corridors, cost, costs, data, data collection, design, development, freight, freight mobility, freight movement reliability, global positioning, global positioning systems, GPS, improvement, methodology, mobility, networks, performance, positioning, probe program, project, research, roadway, software, speed, statistics, Study, System, systems, technology, traffic, traffic data, transportation, travel time, truck, truck monitoring, trucks, volume, Washington, Washington state

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/607.1.pdf http://wsdot.wa.gov/Research/Reports/600/607.1.htm

Abstract:
In 2003, the Washington State Department of Transportation (WSDOT) initiated a research effort to develop and test a methodology for estimating congestion delay on Seattle area freeways. The initial phase of the research developed a preliminary methodology for both measuring congestion and assigning that congestion to specific lane blocking incidents. In Phase 2 of this study, that methodology was automated and extended to include an examination of the effects of incidents occurring on the shoulders of the freeway, spillback from incident-caused congestion on one freeway that affects a second freeway that feeds traffic onto the initially congested facility, special events, and weather. Because funding for this effort was extremely limited, only three corridors (with both directions analyzed independently) and two months of data were analyzed. The project found that the Phase 1 methodology works well in assigning traffic congestion that occurs in the immediate time frame and geographic location of incidents to those incidents. It also showed that this process can be automated, making the data preparation effort now the primary determinant of the cost of additional work of this kind. Unfortunately, even with the addition of shoulder incidents, special events, and weather to lane blocking events, the automated process is unable to assign a significant proportion of the non-recurring delay occurring on Seattle freeways. The detailed analysis of freeway performance showed that much of the delay caused by specific incidents occurs in places or at times removed from the incident itself. The result is that much of the observed non-recurring delay can not be assigned to specific causes by the current analytical process. New analytical procedures will need to be developed in Phase 3 of this work. The Phase 2 analysis also confirmed that the congestion effects of specific incidents and other traffic disruptions are highly dependent on the background traffic conditions at the time of the disruption. While the Phase 2 analysis did not produce all of the results desired, the additional analyses showed that the summary statistics output from the Phase 2 software are useful as input to other analytical procedures.

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

Keywords:
congestion causes, freeway performance, traffic congestion, Washington, Washington state, transportation, WSDOT, research, methodology, congestion, seattle, freeway, developed, incident, Study, effects, traffic, facilities, corridors, data, project, cost, analysis, performance, in-place, condition, statistics, software

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/619.1.pdf http://wsdot.wa.gov/Research/Reports/600/619.1.htm

Abstract:
Increasing traffic volumes and a deteriorating transportation infrastructure have stimulated the development of new systems and methods to accelerate the construction of highway bridges. Precast concrete bridge components offer a potential alternative to conventional reinforced, cast-in-place concrete components. The use of precast components has the potential to minimize traffic disruptions, improve work zone safety, reduce environmental impacts, improve constructability, increase quality, and lower life-cycle costs. This study compared two precast concrete bridge pier systems for rapid construction of bridges in seismic regions. One was a reinforced concrete system, in which mild steel deformed bars connect the precast concrete components and provide the flexural strength of the columns. The other was a hybrid system, which uses a combination of unbonded post-tensioning and mild steel deformed bars to make the connections. A parametric study of the two types of systems was conducted using nonlinear finite element models to investigate the global response and likelihood of damage for various frame configurations. On the basis of this study, a practical method was developed to estimate maximum seismic displacements from the cracked section properties of the columns, the elastic design displacement response spectrum, and the base-shear strength ratio. The results of the global nonlinear finite element analyses suggest that the systems have the potential for good seismic performance. Further analytical and experimental research is needed to investigate the constructability and seismic performance of the connection details.

Authors:
Hieber,D. G., Wacker,J. M., Eberhard,M. O., Stanton,J. F.

Keywords:
Alternative, bridge, bridges, columns, concrete, concrete bridge, connections, constructability, construction, cost, costs, damage, design, developed, development, environmental, environmental impact experimental, finite element, highway, impact, impacts, infrastructure, methods, models, performance piers, precast, precast concrete, prestressed concete, quality, Rapid construction, Regions, reinforce concrete, research, response spectra, response spectrum, safety, seismic, seismic performance, steel strength, Study, substructures, System, systems, traffic, traffic volumes, trasportation, volume

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/611.1.pdf http://wsdot.wa.gov/Research/Reports/600/611.1.htm

Abstract:
TrafficTV is a traffic and traveler information resource available on cable television (UWTV2 Channel 76). It began operation June 1, 1998, as part of the SmartTrek Operational Deployment under the name Traffic Channel. The SmartTrek evaluation of May 2001 identified several problems with Traffic Channel and recommended some improvements. This project made those changes and renamed the application TrafficTV. A series of meetings was held in June 2003. These meetings involved personnel from the Washington State Department of Transportation (WSDOT) Northwest Region, WSDOT Advanced Technology Branch, WSDOT Olympia office, the University of Washington's UWTV, and the UW Intelligent Transportation Systems Research Program. From these meetings came a set of recommended changes. These changes were made to TrafficTV and are documented in this report. Battelle Institute conducted a focus group in May 2004 to evaluate the resulting program. This focus group concluded that TrafficTV is a useful traveler information tool but has not had sufficient public exposure to make it widely known to the traveling public. A market penetration audit conducted by Media Audit in June and July 2004 indicated that when viewers were asked about TrafficTV, over 94,000 had seen the program within the last week. This was deemed surprisingly high, given the lack of external exposure and that viewers would have found TrafficTV only by word of mouth or by "channel surfing." Again, a conclusion of the audit was that additional exposure would make TrafficTV more valuable as a traveler information tool. As a result of the publicity recommendations, a banner has been added to the North West Region's traveler information page to alert users to the availability of TrafficTV.

Authors:
Dailey,D. J., Bradbury,J.

Keywords:
traveler information, cable TV, Intelligent transportation system, congestion information, traffic, evaluation, Washington, Washington state, transportation, WSDOT, intelligent transportation systems, systems, research, program, group, public

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/603.1.pdf http://wsdot.wa.gov/Research/Reports/600/603.1.htm

Abstract:
This research addresses the understanding of, and need for, load spectra in future pavement design procedures and as a stepping stone toward more complete pavement design. The primary objective of this project was to develop truck axle load spectra for Washington State. To do this, axle load data collected at WIM stations throughout Washington State were used. The developed load spectra encompass the principal truck axles on the roadway network: single, tandem, and tridem. Achieving this objective allows the Washington State Department of Transportation, or any state highway agency with analogous traffic patterns, to accommodate the requirements of the 2002 Design Guide, developed through NCHRP Project 1-37A. A secondary objective of this project was to determine whether ESALs obtained from the developed load spectra are significantly different from historical values. Because the developed load spectra are transformable to ESALs, state highway agencies that decide not to use the new guide can still choose to employ the ESALs produced with the load spectra. The project concluded that the developed load spectra are reasonable. For single axles they are comparable to the 2002 Design Guide and MnROAD defaults. For tandem and tridem axles, they are slightly more conservative than defaults of the 2002 Design Guide and MnROAD, but they are still within reason. In addition, the ESALs per vehicle class associated with the developed load spectra are comparable to Washington State historical ESALs for vehicle classes 9, 10, and 13. The use of the newly developed ESALs per vehicle will generally increase design ESALs, but that increase will be due to inclusion of the less predominant vehicle classes (4, 6, 7, 8, and 11).

Authors:
Al-Yagout,M. A., Mahoney,J. P., Pierce,L., Hallenbeck,M. E.

Keywords:
agencies, axle, data, design, developed, development, equivalent single axel load, ESAL, highway, load spectra, pavement, pavement design, performance, project, research, roadway, single axle, traffic, transportation, truck, Washington, Washington state, weigh-in-motion, WIM

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/600.1.pdf http://wsdot.wa.gov/Research/Reports/600/600.1.htm

Abstract:
The Falling weight deflectometer test (FWD) is a commonly used method for the evaluation of the structural performance of pavement systems. In the FWD test, a large weight is raised off the ground and dropped onto a rubber loading pad creating an impulse load representative of the real loading imposed by heavy traffic on the pavement. The excitation produced by the loading sets off waves in the pavement and underlying soil. Deflection time histories are gathered by an array of sensors placed at several nearby locations. The traditional method for interpreting the FWD data to backcalculate structural pavement properties, involves extracting the peak deflection from each displacement trace of the sensors (deflection basin) and matching it through an iterative optimization method to the deflections predicted by a static model of the pavement. This approach is computationally efficient; and when the depths of the layers are known, and their properties are largely homogeneous with depth, the procedure is effective in backcalculating layer properties. However, when the depths are uncertain or when the moduli vary within a layer, the static backcalculation scheme may not yield reliable results.The goal of this study is to investigate the feasibility and effectiveness of using the complete time history of the FWD test to overcome some of the limitations of the static backcalculation procedure, and recover pavement layer moduli distribution and thickness. The problem is also formulated as a numerical minimization problem, where the unknowns are the resilient moduli of thin "computational layers" that discretize the profile. Our initial finding is that this optimization formulation regularized by constraints on the magnitude and spatial gradient of the moduli, coupled with a continuation scheme for imposing the regularization terms, can overcome the ill-posedness nature or the original optimization problem. The computational effort for solving this inverse problem, however, is very significant as it requires repeated calls to the expensive forward problem: an elastodynamic simulation in stiff heterogeneous media. Additional work is needed to speed up the forward problem to be able to perform a more comprehensive evaluation with field data.

Authors:
Turkiyyah,G. M.

Keywords:
research, falling weight deflectometer, weight, evaluation, performance, pavement, systems, traffic, data, moduli, profile, speed

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/586.1.pdf http://wsdot.wa.gov/Research/Reports/500/586.1.htm

Abstract:
This report consists of four sections. The first section provides an overview of the software constructed to service the signs, a description of how the software works, and how to configure the applications. The second section details an experiment requested by Sound Transit in October of 2003. The third section describes results from an experiment in January 2004. The fourth section gives the results of an experiment in April and May of 2004.

Authors:
Mclean,S., Dailey,D. J., Cathey,F. W.

Keywords:
software, traffic, traffic signs, applications, transit

Abstract:
This report documents the development of data collection methodologies that can be used to cost effectively measure truck movements along specific roadway corridors selected by the Freight Mobility Strategic Investment Board (FMSIB.) The intent of this study was to design and test methodologies that could be used to measure the performance of freight mobility roadway improvement projects against benchmarks, or selected standards, which would be used both as part of the project selection process and to report on speed and volume improvements that resulted from completed FMSIB projects. One technology tested was Commercial Vehicle Information System and Networks (CVISN) electronic truck transponders, which are mounted on the windshields of approximately 20,000 trucks traveling in Washington. These transponders are used at weigh stations across the state to improve the efficiency of truck regulatory compliance checks. By using software to link the transponder reads from sites anywhere in the state, the transponder-equipped trucks could become a travel time probe fleet. The second technology tested involved global positioning systems (GPS) placed in volunteer trucks recruited for this project to collect specific truck movement data at 5-second intervals. With GPS data it was possible to understand when and where the monitored trucks experienced congestion. By aggregating this information over time, it was possible to generate performance statistics related to the reliability of truck trips, and even examine changes in route choice for trips between high volume origin/destination pairs. The study found that both data collection technologies could be useful; however, the key to both technologies is whether enough instrumented vehicles pass over the roadways for which data are required. This basic condition significantly affects whether the transponder and GPS technologies will be effective at collecting the data required for any given FMSIB benchmark project . The report also recommends the traffic data that should be collected for a benchmark program and the potential costs of using either data collection technology.

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

Keywords:
freight movement reliability, truck monitoring, development, data, data collection, methodology, cost, truck, roadway, corridors, freight, freight mobility, mobility, design, performance, speed, volume, commercial vehicle, networks, trucks, Washington, software, travel time, probe, global positioning, global positioning systems, positioning, systems, GPS, congestion, statistics, reliability, condition, traffic, traffic data, program, costs

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Abstract:
The intent of this project was to develop retroreflectivity degradation curves for roadway pavement markings. To accomplish this objective, this study utilized a vehicle-mounted Laserlux retroreflectometer to take measurements on approximately 80 test sections throughout Washington state. The resulting retroreflectivity values from roadways with similar average annual daily traffic (AADT) and environments displayed a significant amount of variability. Best-fit trendlines were extrapolated to determine when each category of paint would fall below a selected minimum threshold of 100 mcd/m2/lux and require repainting.Unfortunately, given the variability of the data observed to date, it may not be possible, even with the collection of more data, to create striping performance predictions that have a high level of statistical confidence. According to that schedule, long line painted markings should be painted at least once a year, and heavy wear, long line pavement markings should be painted at least twice a year.

Authors:
Kopf,J.

Keywords:
degradation curves, Laserlux retroreflectometer, pavement, pavement markings, retroreflectivity, roadway, Washington, Washington state, traffic, environment, data, performance, prediction, line

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/592.1.pdf http://wsdot.wa.gov/Research/Reports/500/592.1.htm

Abstract:
This report identifies the key issues that must be considered by state and other highway operating agencies in selecting traffic equipment for collecting the truck volumes and load spectra needed for analysis and design of pavement structures. The report also identifies steps that must be taken to ensure that the equipment performs appropriately and that, as a consequence, the data collected accurately describe the vehicles being monitored. The report is a useful resource for state personnel and others involved in the planning and design of highway pavements and structures.

Authors:
Hallenbeck,M. E., Weinblatt,H.

Keywords:
analysis, data, design, highway, pavement, pavements, structures, traffic, truck, volume, Miscellaneous Library

Abstract:
The purpose of this research was to explore the relationship between roadway and roadside accidentrates for Washington State highways to improve the Washington State Department of Transportation's(WSDOT) process of modeling roadway and roadside accident rates and to arrive at possible improvements in the efficiency of WSDOT's safety project programming process.The project tested the use of the seemingly unrelated regression estimation (SURE) model to modelthe roadway and roadside simultaneously. The theoretical advantage of the SURE approach is that it does not impose any a priori assumptions on the explicit linkage between roadway and roadside accident rates, and there is no theoretical support for explicit linkage, either. The data used to derive this model were from a random sample of 500 one-mile sections from the Washington State highway system. Traffic dataincluded traffic volumes, truck compositions, AADT, traffic speeds, and other relevant information.Geometric data included lane, shoulder, median, curve, and intersection information. Historical weather data such as monthly precipitation and temperature were collected from the National Oceanic and Atmospheric Administration database.In comparing significant explanatory variables between the roadway accident rate and roadsideaccident rate models, very few variables were common. This confirms that it is preferable to specifyseparate functional forms for roadway and roadside accident rates. Empirical results indicated thatcorrelation between roadway and roadside accident rates was insignificant, indicating that efficiency gainsfrom the SURE model would be minimal. The important finding from a programming standpoint is thatjointly modeling the roadway and roadside simultaneously would not result in significant efficiencyimprovements in comparison to the current state-of-the-practice in Washington State.

Authors:
Chayanan,S., Nebergall,M., Shankar,V., Juvva,N., Ouyang,Y.

Keywords:
roadway, roadside, accident rates, safety programming, research, Washington, Washington state, highway, transportation, WSDOT, modeling, safety, regression, linkage, data, traffic, traffic data, volume, truck, speed, median, temperature, database, models

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/562.1.pdf http://wsdot.wa.gov/Research/Reports/500/562.1.htm

Abstract:
This summary report presents an overview of the level of traveler usage (e.g., how many vehicles use the freeways) and travel performance (e.g., how fast they are traveling, where and how often congestion ocurs) on the principal urban freeways in the central Puget Sound area. The freeways studied in this project are managed by the Washington State Department of Transportation (WSDOT) using its FLOW system, a coordinated network of traffic monitoring, measuring, information dissemination, and control devices that operates on urban state and Interstate highways in the central Puget Sound region. Data presented in this report were collected by the WSDOT's freeway surveillance system. The project that led to this report is intended to meet two separate purposes: 1) to enhance WSDOT's ability to monitor and improve its traffic management efforts on Seattle-area highways, and 2) to provide useful information to the public and decision makers about the status of the freeway system's operational performance. This report is primarily intended to meet the second of these objectives. However, the software developed to assist in freeway data analysis for this project and many of the graphics presented in this report are directly applicable to the first objective.

Authors:
Avery,R. P., Ishimaru,J. M., Nee,J., Hallenbeck,M. E.

Keywords:
analysis, Archived Data User Services (ADUS), congestion, congestion monitoring, control, data, flow, freeway, freeway performance, highway, information dissemination, ITS, management, monitoring, performance, public, research, surveillance, traffic, traffic management, traffic monitoring, transportation, urban, Washington, Washington state, WSDOT

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/563.1.pdf http://wsdot.wa.gov/Research/Reports/500/563.1.htm

Abstract:
This report documents the findings of the evaluation of the North Seattle Advanced Traffic Management System (NSATMS) Project. The evaluation was originally designed to analyze the potential transportation benefits and costs of a regional arterial traffic data sharing system that would obtain traffic signal system information (volumes, signal timing plans, etc.) from participating agencies and then share the data among those agencies. The operational goal was to allow each agency to make better control decisions by providing it with real-time knowledge of traffic conditions outside of its own control system boundaries. Because of a series of technical and project management issues, the system as originally envisioned was not successfully implemented. As a result, this evaluation does not include an analysis of direct operational benefits. It does, however, include a discussion of the expected institutional benefits, as well as an extensive "lessons learned" section based on the project team's review of the NSATMS effort. Of particular note were the importance of effective and ongoing lines of project communication, and the critical need to properly evaluate the fundamental nature of the project and provide a well-matched project management structure. The lessons learned from this project provide instructive guidelines for those who are contemplating future ITS system development efforts of comparable scope and complexity. Despite the limited successes of the NSATMS effort, the evaluation team found continued support for the regional arterial ATMS concept within the Puget Sound region. Follow-on research that contributes to a better understanding of the benefits, costs, and technical requirements of an arterial traffic management system is desired by many of the project participants.

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

Keywords:
intelligent transportation systems, advanced traffic management systems, arterial signal control systems, traffic control strategies, Archived Data User Services (ADUS), data sharing, evaluation, seattle, advanced traffic management systems, traffic, traffic management, management, management system, transportation, transportation benefit, benefits, benefit, costs, cost, arterial, traffic data, data, volume, control, condition, ITS, project management, analysis, line, development, ATMS, research

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External Links: http://www.wsdot.wa.gov/research/reports/fullreports/555.1.pdf http://wsdot.wa.gov/Research/Reports/500/555.1.htm

Abstract:
The Service Patrol pilot demonstration in Seattle and Tacoma was managed by the Washington State Department of Transportation (WSDOT) and operated by Washington State Patrol (WSP) cadets and contracted registered tow truck operators (RTTOs). Two other roving services, not funded as part of this pilot effort but included to a limited extent in this evaluation, were the roving patrol service provided by WSDOT on the SR 520 and I-90 floating bridges and the privately sponsored motor assistance vehicle from AAA's RescueVan. The evaluation examines how the similarities and differences among the different service delivery modes (e.g., the intensity of deployment, equipment choices, service delivery, costs) affect the impact of the Service Patrol operation on traffic conditions (e.g., reductions in delay) and the level of motorist satisfaction. This report also discusses feedback by the agencies participating in the Service Patrol program on institutional and operational issues that contribute to or hinder the success of the program. Operational characteristics and operating statistics are reported to convey factors that describe program effectiveness. The results of the study indicate that the use of a combination of service providers has benefits that no single provider can duplicate, and the cost implications of changing the program are small enough that any potential savings would be fairly minor. The pilot project resulted in a variety of intangible benefits, such as improved interagency coordination and cooperation, more efficient utilization of personnel, and a better understanding of each partner's roles and contributions toward congestion relief. The positive viewpoint toward the Service Patrol was uniform, regardless the service mode. Therefore, no significant changes to the existing pilot program are recommended at this time.

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

Keywords:
service patrols, incident response time, traffic delay, traffic safety, research, seattle, Washington, Washington state, transportation, WSDOT, truck, evaluation, floating bridge, bridges, bridge, costs, cost, traffic, condition, program, statistics, benefits, benefit, congestion

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Abstract:
The Washington State Pavement Management System (WSPMS) offers an organized methodology that WSDOT decision makers use to determine optimum strategies for providing and maintaining pavements in a serviceable condition over a given period of time. It also helps improve decision-making efficiency, provide feedback on the consequences of decisions, and ensure the consistency of decisions made at different management levels within WSDOT. Unfortunately, it is not possible, by simply scanning the WSPMS, to pinpoint reasons why pavement sections made of the same general surface materials and subjected to similar traffic and climatic conditions differ in performance. What the WSPMS can do is assist engineers in developing a candidate list of pavement sections with superior and inferior performance. Common characteristics that linkmultiple pavement sections are of particular interest, in part because they may reflect a common practice(e-g., nighttime construction) that leads to superior or inferior performance.This study undertook various extensive analyses and comparisons to help illustrate common attributes of Washington state pavements with superior and inferior performance. The research also reviewed field performance data for Interstate 90 within the 1999 version of the WSPMS. The purpose was to examine all pavement segments on the 480 km of Interstate 90 within Washington state.Reducing variability will allow WSDOT to produce more consistent pavement performance and will allow increasingly effective planning and forecasting. An almost certain byproduct of this increased planning effectiveness will be a more efficient allocation of available funding.

Authors:
Baker,M. J., Mahoney,J. P.

Keywords:
Assessment, condition, construction, data, effectiveness, forecasting, management, management system, materials, methodology, pavement, pavement management, pavement performance, pavement section, pavements, performance, planning, research, superior inferior, System, traffic, Washington, Washington state, WSDOT

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Abstract:
The SWIFT (Seattle Wide-area for Travelers) project was a field operational test of a wide area ITS communications system using a flexible FM sub-carrier High Speed Data System (HSDS). The test was conducted in a partnership with WSDOT, King County Metro Transit, Delco Electronics, Inc., IBM, Seiko Communications Systems, Metro Traffic Control and the Federal Highway Administration. Three devices were used, by the public, to receive the traveler a Delco car radio (capable of providing vector navigation in addition to personal paging and the messages); a Seiko wrist watch pager; and a portable computer (capable of providing graphic displays of traffic advisories and bus positions). After the 15-month test, interviews with the 600 Seattle commuters/participants were conducted to assess user acceptance. A communications study evaluated the adequacy of the HSDS system to disseminate traveler information. Architecture study assessed the effectiveness of the various components to carry out SWIFT operations. institutional issues study documented the history of the project and assessed the institutional issues confronted. A deployment cost study investigated the cost of deployment of a SWIFT system and assessment of potential profitability. The first five reports in this series detail individual aspects of the project.

Authors:
Wetherby,B., Perez,W.

Keywords:
Acceptance, Assessment, bus, computer, control, cost, counties, data, Deployment, effectiveness, evaluation, highway, Institutional, interviews, Issues, ITS, Miscellaneous Library, paging, portable computer, project, public, seattle, speed, Study, SWIFT, System, systems, traffic, traffic advisories, traffic control, transit, traveler information, WSDOT

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Abstract:
Funded by the 1987 Intermodal Surface Transportation Efficiency Act, the Strategic Highway Research Program (SHRP), was a five year, $150 million research program to improve the performance of the nation's roads by addressing four key areas: concrete and structures; highway safety and maintenance; asphalt; and long-term pavement performance. Nearly one-third of the $150 million was allocated for the study of asphalt, specifically to develop performance based specifications that would relate material properties of the binder and the mix to field performance. Superpave (Superior PERforming asphalt PAVEments) encompasses the products of the SHRP asphalt research program and consists of three interrelated elements: an asphalt binder specification with supporting tests; a mix design and analysis system with supporting tests; and performance prediction models. This report is a compilation and synthesis of Washington DOT's (WSDOT) experience with selected components and concepts of the SHRP/Superpave technology to include the following: performance graded (PG) binder usage and specification validation; gyratory mix design; the Superpave Shear Test (SST); and field performance of the Superpave mixes.Binders typically specified by WSDOT (AR400OW and PBAs -2, -5, -6. -6GR) were classified in terms of five Superpave performance grades: PG 58-22; 64-22; 64-28; 64-34; and 70-28. Although data from 171 weather stations suggest that as many as 6 low- and 5 high-temperature grades could be specified, binder availability and regional pavement distress were used to develop guidelines for statewide PG usage. Three binders were recommended for use in the western, northeastern and southeastern regions of the state as follows: PG 58-22; PG 58-34; and PG 64-28, respectively. Validation of the binder specification with respect to low temperature cracking was accomplished using binder and field performance data from 28 projects. The results were very encouraging: the original SHRP algorithm for binder selection correctly "predicted" field performance in 22 of 28 cases, whereas the LTPP algorithm for binder selection correctly "predicted" field performance in 26 of 28 cases.Additionally, a laboratory experiment using the Superpave Shear Test (SST) apparatus was undertaken to test the effectiveness of binder "bumping," i.e., increasing the high temperature grade because of exceptionally high traffic volume and/or slow or standing traffic. The data clearly indicate that the SST is an effective tool for discriminating between binders and that 'bumping" may be effective in reducing pavement rutting. Permanent shear strain for specimens made with a PB 70-xx binder was only 25 to 33% of the shear strain for specimens made with a PG 58-xx binder.As originally configured, the Superpave mix design matrix included seven traffic levels and four temperature regimes for 28 possible compaction levels. Recognizing that the 28 compaction levels made for a somewhat unwieldy system, WSDOT attempted to reduce the number of compaction levels by conducting a series of mix designs at each compaction level. The results of the limited experiment suggest that it might be possible to limit the number of compaction levels required for mix design. Research by Brown et. al. (NCHRP 99) tends to confirm this as they have suggested reducing the number of compaction levels and provided more definitive guidance with respect to each level.Since 1993 WSDOT has place 44 projects which include some component of the Superp ave technology. For 17 of these projects parallel Hveem and Superpave mix designs were conducted. In 13 of the 17 cases, the Superpave design asphalt content was equal to or greater than the Hveem design asphalt content, though the difference was usually no more than 0.2%. A fundamental difference between Hveem and Superpave mix design methods is the compaction device. Data from these field projects indicate that the current kneading and gyratory compaction protocols (at least for 109 gyrations) yield similar air void contents.As noted previously, Washington DOT has placed 44 projects which involve some component of the Superpave technology. For 18 of the projects a conventional Hveem mix design was conducted using a PG binder (Hveem-PG). The remaining 26 projects were truly Superpave, i.e., the materials selection and mix design were established in accordance with the Asphalt Institute's SP2, Superpave Level 1 Mix Design. According to WSDOT practice the following numerical indices trigger maintenance: Pavement Structural Condition (PSC) 10 mm; or International Roughness Index (IRI) > 500 cnVkm. Although relatively "young", the 44 projects are performing quite well. The average values of rutting, PSC, and IRI (4, 91, and 121, respectively) are all well below the "trigger" values. With respect to rutting and PSC, the performance of Hveem-PG and Superpave projects is virtually identical. However, the ride quality of the Superpave projects is a bit rougher than the Hveem-PG binder projects: IRI of 134 for the former and 103 for the latter. The higher values of IRI measured on the Superpave projects may be the result of the typically coarser aggregate gradation or differences in construction techniques.WSDOT's Superpave experience has not been without challenges. Still, its overall experience has been very encouraging. Experimentation with the revised compaction matrix, continued use of the SST, field validation of the "bumping" experiment, and long-term monitoring of field performance will provide the necessary data to allow WSDOTs critical assessment of Superpave's technical merit and economic viability.

Authors:
Leahy,R. B., Briggs,R. N.

Keywords:
SHRP, Superpave, asphalt, intermodal, transportation, transportation efficiency, highway, research, program, performance, concrete, structures, highway safety, safety, maintenance, pavement, specifications, specification, asphalt pavement, pavements, tests, design, analysis, prediction, models, Washington, WSDOT, data, temperature, cracking, LTPP, traffic, volume, compaction, materials, condition, international roughness index, roughness, index, ride quality, quality, aggregate, construction, ITS, monitoring

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Abstract:
This annual meeting covered a wide variety of transportation issues. Bridge and Design issues were discussed, material and pavement specification, as well as strategic planning and traffic control.

Authors:
Anderson,K. W.

Keywords:
69th, Annual, bridge, control, design, Meeting, pavement, planning, specification, strategic planning, traffic, traffic control, transportation, TRB

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Abstract:
The Seattle Wide-area Information for Travelers (SWIFT) project was a highly successful Intelligent Transportation System (ITS) Field Operational Test (FOT) that was conducted over a four-year period from 1993 to 1997. The purpose of the project was to test the efficacy of a High Speed Data System (HSDS), or FM Sub-carrier, to disseminate incident, bus and speed congestion information via three different end-user devices: pager watch, portable computer and in-vehicle navigation device. Six hundred ninety (690) commuters, many with route- or mode-choice options, participated in the FOT and provided user-acceptance evaluations. Other evaluation components examined the system architecture, communications coverage, deployment cost and institutional issues that affected the project.The primary purpose of the SWIFT Institutional Issues Study evaluation was to collect information regarding the institutional issues (e.g., policies, jurisdictional issues, internal and external factors) that affected design, development, testing, deployment and conduct of the SWIFT Field Operational Test (FOT); determine how these issues were overcome and what lessons could be learned. A secondary purpose of the evaluation was to document the history of the SWIFT project.The methodology for the SWIFT Institutional Issues Study consisted of two sets of questionnairesand two sets of semi-structured interviews that were conducted with fourteen (14) SWIFT team memberrepresentatives at two different points during the conduct of the SWIFT FOT: about midway through the conduct of the test and after the test was completed. All SWIFT team member responses were independently collected and SWIFT institutional issues were primarily identified by determining which topics were addressed by two or more individuals. Historical information was collected from various sources throughout the project.SWIFT represents one of the first ATIS FOTs conducted in this country. Earlier tests were conducted in Orlando, FL (TravTek) and Minneapolis St. Paul (Genesis) among others, yet the SWIFT FOT appears to have extended considerably the available database of information regarding ATIS effectiveness and acceptance. The addition of real-time bus information, in particular, has set the SWIFT FOT apart from others already conducted.One of the significant aspects of the SWIFT teaming agreement was the long-term interest in ITS and commitment of the organizations involved. For instance, the majority of the SWIFT team members articulated a long-term interest in ITS deployments. In addition, three organizations-Seiko, Etak and Metro Traffic Control-+ommitted themselves to fielding a \"SWIFT-like\" system after the project was completed. This degree of interest and commitment resulted in all of the SWIFT team members working together in a very effective, cooperative fashion throughout the FOT.A critical organizational structure that was instituted to implement SWIFT was the weeklyteleconference. This simple, yet cost-effective method of managing and discussing the technicalissues involved with the project was attributed by many of the SWIFT team members to aprimary instrument of the project\'s success. In particular, the SWIFT teleconferences enabledthe representatives of each organization to keep abreast of the developmental status of theproject, to brainstorm solutions to encountered problems and to develop scheduling sense.

Authors:
Wetherby,B.

Keywords:
ATIS, bus, computer, congestion, congestion information, cost, data, database, design, development, effectiveness, evaluation, incident, Institutional, Intelligent transportation system, interviews, Issues, ITS, methodology, mode choice, policy, portable computer, project, scheduling, seattle, speed, SWIFT, System, tests, traffic, transportation

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Abstract:
The Seattle Wide-area Information for Travelers (SWIFT) Operational Test was intended to evaluate the performance of a large-scale, urban Advanced Traveler Information System (ATIS) deployment in the Seattle area. With the majority the SWIFT system completed by June 30,1996, the SWIFT Field Operational Test (FOT) evaluation was conducted from July 1, 1996 through September 20, 1997. The unique features of the SWIFT ATIS included the provision of information for multiple transportation modes, the delivery of this information using three different devices and the use of FM sideband as the primary communications medium. A total of 690 system users were recruited during the course of the study, including 520 Seiko Message watch users, 90 users of the Delco in-vehicle-navigation device and 80 users of the SWIFT portable computers.Purpose of Test. The SWIFT Consumer Acceptance Study was one of five component studies to the overall system evaluation. This report details the findings for the SWIFT Consumer Acceptance Study based on the evaluation objectives that were identified in the SWIFT Evaluation Plan (1 995). The primary objectives of the SWIFT Consumer Acceptance Study were to assess the following:Importance of traveler information in travel planningUsefulness of SWIFT traveler information in travel planningMinimum set of user services and device features required to provide viable productand servicesUser perceptions of SWIFT device usefulnessWillingness-to-pay for different services.User perceptions of changes in travel convenience and efficiencyUser perceptions of changes in traffic congestion, air quality, energy consumption,and safety.Additional SWIFT Consumer Acceptance Study objectives, conducted in support of the SWIFTArchitecture Study, were to assess the following:SWIFT system reliability from a user perspectiveSWIFT system availability from a user perspective.Methods. A variety of data-collection efforts were completed, including questionnaires, focus groups and telephone interviews. The questionnaires contained items that addressed objectives set out in the evaluation plan. The focus groups were conducted with small groups of users to obtain qualitative impressions from a smaller subset of users who were encouraged to speak openly and share their perceptions with other users. The SWIFT Consumer Acceptance Study focused on measurement and analysis of user perceptions toward SWIFT system usefulness and performance. No attempt was made to quantify the system level impacts of SWIFT services on congestion, air quality, energy consumption or safety in the Seattle region. Rather, the assessment of system-level transportation impacts was limited to examining subjective data (e.g., traveler's perceptions) collected from users and determining whether these perceptions were consistent with a benefit.Perceptions of Importance of Traveler In formationResults indicated that SWIFT users tended to place a high degree of importance on incident and congestion-related information in travel planning. Incident location and duration information was rated quite high in importance along with general traffic congestion information. For the group as a whole, information concerning bus schedule and route information and bus-location information was rated very low in importance, although these ratings were much higher in those users that actually used the bus. This was consistent with the automobile dependence reported by the group, and suggests that information concerning non-automobile options would not be used by the automobile-dependent group. Since users of the SWIFT portable computer were recruited from among transit users, this group generally rated transit information higher than other device users groups. However, the importance of this information was not as high as congestion and incident-related information. Receipt of various general-information messages was not rated very high in importance by questionnaire respondents, with the exception of weather, sports and news items. Most SWIFT respondents indicated that the receipt of financial and other environmental information was not important. Of course, from a transportation-impact point of view, the receipt of these general information messages was inconsequential. However, if device users were attracted by thesemessages it may make such services commercially viable to augment any potential benefitperceived by users through the receipt of travel-related information.Perceptions of S WIFT Traveler In formation UsefulnessUsers tended to view the messages they received from the SWIFT systems as accurate, reliable,timely, easy to understand and useful. Among device types, respondents representing users of the Seiko Message Watch expressed concern with the timeliness of incident-related messages. In addition, these respondents tended to rate ease of understanding lower than other user groups. Users of the Delco in-vehicle-navigation devices and SWIFT portable computers experienced problems in receiving personal-paging messages and these problems were reflected in respondent ratings. The map-based display provided by the SWIFT portable computer resulted in generally higher ratings for this device over other devices in understanding incident location and the nature of congestion. Seiko Message Watch users reported difficulty in understanding the extent of expected delay as well as the nature of congestion, while Delco in-vehicle-navigation device respondents reported difficulty in understanding the period of time for which a message applied. Generally speaking, SWIFT participants endorsed a wide-range of improvements to messages provided by the SWIFT system. Most seemed to consider the operational test as a suggestion of what might be possible, rather than a demonstration of a final product. Among Seiko Message Watch users, respondents expressed a desire for improved timeliness of messages as atop priority.

Authors:
Trombly,J., Wetherby,B., Dixson,A.

Keywords:
Acceptance, air quality, analysis, Assessment, ATIS, availability, bus, computer, congestion, congestion information, Consumer, data, data collection, Energy, environmental, evaluation, group, impact, impacts, improvement, incident, interviews, Miscellaneous Library, objectives, performance, planning, portable computer, quality, reliability, safety, seattle, Study, SWIFT, System, systems, traffic, traffic congestion, transit, transportation, travel, traveler information, urban

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Abstract:
This working paper, 'Travel Patterns in Mixed Use Neighborhoods,' summarizes Phase I of a research effort by the Innovations Unit of the Washington State Transportation Commission. The study is based on previous Innovations Unit research, described in the 1992 report, Land Use-Transportation Linkage (Kestle et al. 1992), the focus of which was the impact of land use policies on transportation systems. This working paper describes surveys conducted in four neighborhoods in the state of Washington (three in King County and one in Spokane) to gather data on travel behavior in neighborhoods that have a good mix of housing, shopping, and services; in other words, mixed use neighborhoods. The survey consisted of telephone interviews to determine household characteristics and the subsequent collection of travel diaries to assess household travel habits by mode and purpose. Preliminary results indicate the preponderance of trips for both family and personal business on both weekdays and weekends. Although auto is the dominant mode, results indicate the potential for shared rides in all neighborhoods and for the walk mode in the in-city neighborhoods. Directions for future research are suggested, including the study of the potential for reducing vehicle miles traveled (VMT) in mixed use neighborhoods; the relationships among mixed use development, household demographics, and travel behavior; the possibility of substituting walking for auto use; and methods for alleviating weekend traffic congestion based on a better understanding of the components of weekend travel.

Authors:
Zemotel,L., Nielsen,K., Rutherford,G. S., Ishimaru,J. M.

Keywords:
mixed use, research, innovation, Washington, Washington state, transportation, linkage, land use, land-use, policy, systems, survey, counties, data, travel behavior, behavior, development, walking, traffic, traffic congestion, congestion

Abstract:
This report describes the use of an optimal recursive predictor (Kalman predictor) with inductance loop data to produce an anomaly detector. It details the construction of the system function or transition matrix used in the optimal predictor directly from the statistics of the problem. It demonstrates the use of a prediction algorithm using inductance loop data gathered on Interstate 5 in Seattle, Washington. It discusses the scaling and values of thresholds necessary for anomaly detection. This type of dynamic prediction and threshold can be valuable to traffic management systems that rely heavily on inductance loop data.

Authors:
Dailey,D. J.

Keywords:
traffic surveillance and control, inductive loops, volume occupancy, kalman filter, anomaly detection, traffic

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Abstract:
The Washington State Department of Transportation will be conducting experimental field testing of several selected polymer concrete thin (1/4 inch) overlays over a ten-year period. The polymer concrete material is manufactured by private industry firms and installed on selected bridge decks under standard WSDOT construction contracts. Approximately 21 bridges will be involved in the experiment; eight of these are included in federal participating projects as experimental features.Washington State Department of Transportation will be conducting experimental field testing of several selected polymer concrete thin (1/4inch) overlays over a ten-year period. The polymer concrete material is manufactured by private industry and installed on selected bridge decks under standard WSDOT construction 21 bridges will be involved in the experiment; eight of these are included in federal participating projects as features. The polymer concrete thin overlays were applied to the decks of the River Bridge and the Yakima River Bridge under Contract No. 3 SR 90 and SR 82, Interchange to Terrace Heights. Both bridges are steel truss bridges located on SR 82 just outside Yakima, Washington. Both the epoxy overlay and the methacrylate overlays were versatile products apply under difficult traffic control conditions. Starting and stopping the various pours to accommodate opening and closing of lanes for traffic proved satisfactory. To the extent possible, work was performed at night when traffic was light. All three lanes were then opened to traffic in the early morning to accommodate peak traffic conditions.

Authors:
Roper,T. H., Henley,E. H. Jr

Keywords:
bridge, bridge deck, bridge deck repairs, bridge decks, bridges, concrete, condition, construction, contracts, control, Deck, Epoxy, experimental, lanes, light, overlay, overlays, polymer, polymer concrete, steel, steel truss bridge, thin overlay, traffic, traffic control, transportation, Washington, Washington state, WSDOT

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Abstract:
Three types of stripping materials installed in recessed grooves are evaluated for reflectivity and durability. Initial performance evaluations have two of the materials showing very little wear and providing good daytime delination but marginal nighttime delineation. The other material is showing considerable damage in the form of cracking and spalling and is providing good nighttime delineation but only marginal daytime due to the loss of material.

Authors:
Deer,R., Mansfield,C.

Keywords:
cracking, damage, delineation, durability, evaluation, grooves, lane lines, line, materials, performance, performance evaluation, reflectivity, stripping, traffic

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Abstract:
Various methods of controlling traffic through construction zones are examined. The accident statistics concerning construction flagging are summarized, indicating the need for improvements in construction flagging techniques. A research methodology is presented for implementing and evaluating several flagging techniques.

Authors:
Hinze,J., Ifie,A. O.

Keywords:
construction, construction flagging, evaluation, flagging techniques, highway, highway construction, methodology, research, statistics, traffic, traffic control

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Abstract:
The use of BoniFibers fiber reinforced Asphalt Concrete Pavement (ACP) at three City of Tacoma intersections is reported. Product selection, fiber reinforced ACP mix design, old pavement removal, construction and evaluations are documented.BoniFibers fabric reinforced ACP appears to provide a durable roadway at intersections that have a high volume of turning and heavy traffic. Continued monitoring of the City of Tacoma fiber reinforced ACP is recommended until major deterioration occurs.

Authors:
Toney,C. A.

Keywords:
asphalt, asphalt concrete, Asphalt Concrete pavement, Bonifibers, concrete, construction, design, deterioration, evaluation, fiber Reinforced ACP, fiber reinforced pavement, monitoring, pavement, pavements, Polyester Fibers, Polymar Fibers, roadway, traffic, volume

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Abstract:
The Washington State Department of Transportation will be conducting experimental field testing of several selected ploymer concrete thin overlays over a ten-year period. The ploymer concrete material is manufactured by private industry firms and installed on selected bridge decks under standard WSDOT construction contracts. Approximately 14 bridges will be involved in the experiment.The study was conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration. The Washington State Department of Transportation will be conducting field testing of several selected concrete thin overlays over a ten-year period. The polymer concrete material is manufactured by private industry and installed on selected bridge decks under standard WSDOT construction contracts. 14 bridges will be involved in the experiment. The Snake River Bridge at Clarkston, Washington, Bridge No. 12/915, is the first bridge of the to receive a 1/4 thin overlay. The polymer concrete used is by Polycarb. The deck was repaired and overlaid in June of 1986. Work on the thin overlay began on June 8 and was completed on June 20. A total of 6,477 S.Y. of overlay was involved. Traffic was accommodated at all times on the portion of the bridge not being overlaid. Construction progressed relatively smoothly per the inspector\'s report. The material permitted the contractor flexibility in the rate of installation and in starting and stopping the work. Width of installation was varied to accommodate temporary traffic lanes. Pavement skid tests and bond tests all proved satisfactory. Ninety-one percent of the resistivity tests exceeded the minimum required by the specifications. The majority of the test points that did not meet the minimum specified occurred at the beginning of the work, where the contractor attempted to apply the material with spray that apparently did not provide accurate proportionate mix of the epoxy components. Subsequent tests and reports delamination, half-cell, chloride content, and rutting values to the original deck survey values.

Authors:
Roper,T. H., Henley,E. H. Jr

Keywords:
bridge, bridge deck, bridge deck repairs, bridge decks, bridges, chloride, concrete, construction, contracts, Epoxy, experimental, half-cell, highway, lanes, overlay, overlays, pavement, polymer, polymer concrete, specification, specifications, survey, tests, thin overlay, traffic, transportation, Washington, Washington state, WSDOT

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Abstract:
The Washington State Department of Transportation will be conducting experimental field testing of several selected polymer concrete thin (1 1/4 inch) overlays over a ten-year period. The ploymer concrete material is manufactured by private industry firms and installed on selected bridge decks under standard WSDOT construction contracts. Approximately 21 bridges will be involved in the experiment; eight of these are included in federal participating projects as experimental features.The Grays River Bridge at Roseburg, Washington, Bridge is the second bridge of the federal aid projects to receive a thin concrete overlay. The polymer concrete used was Degadur 330, made by Degussa Company and installed by Floor. The deck was overlaid in August of 1986. Work on the thin overlay began on August 4, 1986 and was completed on August 5, 1986. A total of 586 S.Y. of overlay was placed. There was no traffic on the bridge during the overlay placement. The overlay contractor had a well trained crew and the overlay placement went very smoothly. The experience showed when the different operations of primer, overlay, and sealer were sequenced so that when one layer cured out, the next operation was ready to go. Friction tests and electrical resistivity tests were all satisfactory.

Authors:
Roper,T. H., Henley,E. H. Jr

Keywords:
bridge, bridge deck, bridge deck repairs, bridge decks, bridges, concrete, construction, contracts, experimental, friction, overlay, overlays, polymer, polymer concrete, sealer, tests, thin overlay, traffic, transportation, Washington, Washington state, WSDOT

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Abstract:
This is the post construction and one year evaluation Report of being used as the wearing course on a bridge deck overlay under very high traffic volumes. A rubberized Class D Asphalt Concrete Pavement friction course was used on an adjacent bridge to compare against the PlusRide. The properties evaluated were friction resistance, noise, fatigue properties and deicing characteristics. The friction and noise properties are the same. The PlusRide has deeper ruts and large areas in the traveled lane have delaminated. The deicing characteristics have not been confirmed. The rubberized class ACP is performing better than the PlusRide.

Authors:
Peters,A. J., Schultz,R. L.

Keywords:
asphalt, asphalt concrete, Asphalt Concrete pavement, asphalt pavement, bridge, bridge deck, bridge deck overlay, bridges, Class D, concrete, construction, Deck, evaluation, fatigue, friction, friction course, noise, overlay, pavement, PlusRide, resistance, Rubberized, traffic, traffic volumes, volume

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Abstract:
The Telecom Link established between the University of Washington and the WSDOT Traffic Systems Management Center (TSMC) was updated during this project in order to handle the shift made by the TSMC from a 1700 loop surveillance system to a 2200 loop system. Special computer programs were also written to provide specialized summary statistics for key stations. The new software allowed statistics for key stations to be collected and summarized during data transfer. The entire transfer retrieval system was streamlined during the Telecom project to reduce costs. Finally, freeway incident analysis was performed with a data set to demonstrate the use of the new system for TSM research.

Authors:
Nihan,N. L.

Keywords:
analysis, computer, computer program, cost, costs, data, data management, data transfer, freeway, freeway surveillance and control, incident, management, program, ramp metering, research, software, statistics, surveillance, systems, telecommunications, telecommunications link, traffic, traffic systems management, transportation systems management, TSM, Washington, WSDOT

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Abstract:
The Washington State Department of Transportation (WSDOT) designed and installed Service Level 1 (SL-1) bridge rails on three treated timber bridges in the state. To date there have been no accidents or maintenance problems reported at any of the modified bridges.

Authors:
Gripne,D.

Keywords:
accidents, bridge, Bridge rail modification, bridges, maintenance, Rail for Timber Bridge, systems, traffic, transportation, Washington, Washington state, WSDOT

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Abstract:
A changeable message sign to inform, warn and direct traffic was installed in Vancouver, Washington prior to the initiation of major reconstruction on the Interstate 5 corridor. Despite some operational problems, the sign proved to be of considerable value in informing motorists of the changing roadway configurations necessitated by the construction operations. The use of similar signs in other locations was recommended.

Authors:
Blodgett,F. J.

Keywords:
Changeable message sign, construction, reconstruction, roadway, traffic, Washington

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Abstract:
This study involved an in-depth evaluation of the Washington State Department of Transportation highway data development and analysis activities. It developed statistically-based procedures and recommendations for a streamlined highway data collection program. Opportunities to reduce manpower and equipment costs, streamline work activities, improve the quality of data collection and provide accurate and timely data for the various users were identified. Given the focus on highway data, the major effort was devoted to the Department's traffic counting program. However, many data items and programs were considered, with the following receiving particular attention: traffic volume counting, including estimation of annual average daily traffic at any location throughout the state highway system; associated seasonal, axle and growth factors; vehicle classification; truck weights; and the relationship between the statistical sampling requirements recommended for these items and those associated with the FHWA Highway Performance Monitoring System in the state.

Authors:
Ritchie,S. G., Hallenbeck,M. E.

Keywords:
analysis, Annual, axle, cost, costs, data, data collection, developed, development, equipment, evaluation, highway, monitoring, performance, performance monitoring, program, quality, sampling, seasonal, Study, System, traffic, traffic counting, transportation, truck, vehicle classification, volume, Washington, Washington state, weight, weights

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Abstract:
The use of liquid anti-stripping additives (LAA) for reducing moisture damage in asphalt concrete pavements was evaluated using pavement cores from pairs of projects with-and-without LAA. Results were analyzed using the tensile strength ratio (TSR). In addition, a diazo-dye for determining the presence and concentration of LAA was attempted to access the value or the test as a field procedure. The chemical additive detection tests proved inclusive, but the TSR analysis gave a positive indication of the need for the use of LAA in the wetter environments of the state, For drier environments and for low traffic volumes, use of LAA may not be cost effective. The indirect tensile test was judged to be a potentially valuable tool for statewide use in the evaluation of stripping additive needs.

Authors:
Malsch,D. A.

Keywords:
additive, analysis, anti-stripping agents, asphalt, asphalt concrete, Asphalt Concrete pavement, bituminous concrete, Chemical, concrete, cost, cost effective, damage, detection, diazo-dye test, effectiveness, environment, evaluation, indirect tension test, moisture damage, pavement, pavement life, pavements, project, strength, stripping, tests, traffic, traffic volumes, volume

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Abstract:
This report describes a newly established telecommunications link between Seattle\'s Traffic System Management Center (TSMC) and the University of Washington\'s (UW) Information Retrieval System. Volume data in five-minute intervals collected by the TSMC is transferred to the UW computer system. The reports contains a description of this 1 ink and a User\'s Guide for those who wish to access the data.

Authors:
Nihan,N. L.

Keywords:
computer, data, freeway surveillance, information retrieval, management, seattle, System, systems, telecommunications, telecommunications link, traffic, traffic systems management, traffic volumes, volume, Washington

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Abstract:
The study is reported in two volumes. The first volume summarizes the state-of-the-art on pavement overlay design and presents a research plan to develop an overlay design procedure for the Washington State Department of Transportation (WSDOT) The second volume contains an annotated bibliographyof significant pavement overlay literature published since 1968.The state-of-the-art review presented in Volume I addresses pavement evaluation using nondestructive testing and subjective ratings. These are discussed along with the topics of traffic and seasonal variations. Pavement overlay design concepts are identified and discussed. A research plan is presented forthe development of a pavement overlay design system for WSDOT.

Authors:
Newcomb,D. E., Bubushait,A. A., Mahoney,J. P., Sharma,J.

Keywords:
design, development, evaluation, nondestructive testing, overlay, pavement, pavement evaluation, performance, research, review, seasonal, seasonal variation, seasonal variations, state-of-the-art, Study, System, traffic, transportation, volume, Washington, Washington state, WSDOT

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Abstract:
This report is presented in two volumes. The first volume summarizes the Final Report Sept. 15 - Dec. 15, 1983 14. Sponsoring Agency Code state-of-the-art on pavement overlay design and presents a research plan to develop an overlay design procedure for the Washington State Department of Transportation (WSDOT) . The second volume contains an annotated bibliography of significant pavement overlay 1iterature pub1ished since 1968.The state-of-the-art review presented in Volume I addresses pavement evaluation using nondestructive testing and subjective ratings. These are discussed along with the topics of traffic and seasonal variations. Pavement overlay design concepts are identified and discussed. A research plan is presented for the development of a pavement overlay design system for WSDOT,

Authors:
Newcomb,D. E., Bubushait,A. A., Mahoney,J. P., Sharma,J.

Keywords:
agencies, design, development, evaluation, nondestructive testing, overlay, pavement, pavement evaluation, performance, research, review, seasonal, seasonal variation, seasonal variations, state-of-the-art, System, traffic, transportation, volume, Washington, Washington state, WSDOT

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Abstract:
The Washington State Department of Transportation (WSDOT) designed and installed Service Level 1 (SL-1) bridge rails on three treated timber bridges in the state. To date there have been no accidents or maintenance problems reported at any of the modified bridges.

Authors:
Gripne,D.

Keywords:
accidents, bridge, Bridge rail modification, bridges, maintenance, Rail for Timber Bridge, systems, traffic, transportation, Washington, Washington state, WSDOT

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Abstract:
Statewide sampling of highway runoff continued through 1980-81, and the resulting data has been aggregated with that from previous years to further investigate pollutant loadings. Results have validated the solids loading model previously proposed by Asplund (1980) for Western Washington Highways and tentatively extended the model to Eastern Washington. Loading of there pollutants can be predicted from total suspended solids loading using ratios derived from the data. These ratios may be taken as constants at any Washington State location for some pollutants or as linear functions of traffic or other contaminants. Comparison of runoff from a sulfur-extended asphalt pavement with runoff elsewhere indicates higher sulfate loads in the former case. A limited sampling program along an uncurbed highway section observed higher pollutant concentrations from these sections to curbed areas. Sampling of solids adhering to the undercarriage of automobiles produced widely varying results but suggested that vehicles traveling on rural or unpaved roads accumulate significant amounts of solids that can be released on highways. The final year of field sampling will concentrate on improving the loading models, especially for Eastern Washington application, and continuing the sulfur extended asphalt study with a functional control site experiencing the same conditions.

Authors:
Tai Wik,David Chui, Mar,B. W., Horner,R. R.

Keywords:
analysis, asphalt, asphalt pavement, Concentrations, condition, control, data, extended asphalt, highway, highway runoff, Highways, loads, model, models, pavement, pollutant loading, Pollutants, program, runoff, rural, sampling, statistical analysis, sulfur, suspended solids, traffic, Washington, Washington state

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Abstract:
The purpose of the study is to determine how distinctive social, economic, land use, governmental and political characteristics in the Vancouver-Portland area to uneven growth which in turn affects the transportation system. Interviews with public and private industrial representatives to identify the reasons underlying uneven growth are discussed. A statistical analysis of population, employment, vehicle registration and traffic across the Interstate 5 bridge connecting Vancouver and Portland is also presented. Recommendations are listed which suggest ways to improve the transportation system through modification of elements contributing to uneven growth.

Authors:
Public Transportation and Planning Division, Washington State Department of Transportation

Keywords:
analysis, bi-city, bi-state, bridge, economic development, employment, industrial location decision, interviews, land use, land use sewerage, land-use, population, public, statistical analysis, Study, System, traffic, traffic volumes, transportation, Uneven growth rate

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Abstract:
This small car accident study investigated accidents in Washington State in four passenger car categories: subcompact, compact intermediate, and large. The primary purpose of the study was to evaluate the effects on safety of increases in the number of smaller cars on the highways. Traffic accident data for the period 1973-79 were analyzed to determine the accident severity for the different automobile classes, and this analysis showed that the smaller vehicles had a higher proportion of fatal and injury accidents that the other categories.The, accident data for 1980 were used to compare accident experience with regard to injury class of the occupants, roadway surface conditions, roadway character, light conditions, collision type, objects struck, and location of accident. Analysis showed that for total accidents per one thousand registered vehicles, the large cars had a higher rate (68) than either the subcompacts (43), compacts (45), or intermediate size vehicles (46). However, the subcompacts and compacts had higher percentages of fatalities and serious injuries to their occupants, and a higher proportion of such accidents occurred on wet, snowy, and icy surfaces. In addition, the smaller passenger vehicles had a higher incidence of overturning and rear-end accidents. The analysis suggests there will be significant increases in fatal and injury accidents in future years as the number of smaller vehicles increases. Thus, the report contains recommendations for changes in highway and vehicle design that will modify these adverse trends and reduce injuries and fatalities among drivers and passengers.Some of the recommendations can be implemented fairly quickly, but others will take longer. However, until changes are made, the accident severity for small cars will continue at a level above that for larger automobiles.

Authors:
Public Transportation and Planning Division

Keywords:
accident severity, accidents, analysis, collision, condition, data, design, highway, Highways, light, overturning, roadway, safety, Study, traffic, traffic accident data, Washington, Washington state

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Abstract:
A highway storm water runoff pollutant loading. model has been developed based on results from con3posire sampling of approximately 600 storms at nine locations in the State of Washington over five years. The model expresses total suspended solids (TSS) loading in proportion to the product of highway segment length, average runoff coefficient, and vehicles traveling during storm periods. It was dem-onstrated that loadings of contaminants such as chemical oxygen demand, nutrients and trace metals could be estimated from TSS loadings using ratios derived from the data, The model described was developed and validated for assessing total loadings over a time span encompassing a number of storms (monthly or annually). To predict pollutant concentrations and loadings in runoff from a given storm, cumulative distributions were plotted and analyzed to determine the probability of exceeding specific concentration and loading values in a given case. Bioassay studies using highway runoff indicated toxicity to aquatic life when elevated metals deposition from high traffic volumes (in excess of 10,000 -20,000 vehicles per day) or high metals concentrations in rainfall caused runoff concentrations to exceed lethal levels. Draining highway runoff through grass channels 60 meters in length greatly reduced TSS and metals concentrations and the consequent toxic effects. The major product of this research is a guide to assessing and mitigating the impacts of highway runoff to receiving waters.

Authors:
Mar,B. W., Horner,R. R., Spyridakis,D. E., Welch,E. B.

Keywords:
Assessment, Channel, Chemical, Concentrations, data, demand, deposition, developed, highway, highway runoff, impact, impacts, Loadings, Highway runoff, metals, mitigation, model, models, pollutant loading, Pollutants, quality, rainfall, research, runoff, sampling, span, stormwater, suspended solids, Toxicity, traffic, traffic volumes, volume, Washington, Washington state, water quality

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Abstract:
A total of 241 storm events were sampled at ten sites during the first full year of statewide monitoring of highway runoff. Analyses of these data indicates that more than half of the observed solids in this runoff is traced to sanding operations. The total solids loading at each side-was correlated with traffic during the storm. The ratio of other pollutants to solids was linear when there was sufficient traffic-generated pollutants to saturate the available solids.

Authors:
Asplund,Randy L., Ferguson,John F., Mar,B. W.

Keywords:
data, highway, highway runoff, models, monitoring, Pollutants, runoff, traffic, Washington, Washington state, Water Pollutants, Washington State Monitoring

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Abstract:
Two forms of pavement distress were noted on recent asphalt concrete overlay projects. A general loss of wearing surface under traffic action, termed surface ravelling, was observed on three projects starting the first season after construction.Two forms of pavement distress were noted on recent asphalt concrete overlay projects. A general loss of wearing surface under traffic action, termed surface ravelling, was observed on three projects starting the first season after construction. A concentrated, local loss of surface material in narrow longitudinal strips, designated as strip ravel ing, was observed on four projects approximately the second season after completion. Construction record reviews and field testing and sampling of these projects along with four undistressed projects were made to define the construction methods and equipment used and to obtain samples from areas of good and bad pavement condition. These samples were tested to determine the strength of the compacted mix, and of the aggregate and asphalt constituents. Common factors from the projects showing surface ravelling were a thin lift pavement overlay placed late in the paving season with a tendency toward less than optimum asphalt content. The resulting pavement had high air void content and was readily abraded by traffic during ensuing severe winter weather. Recurrence of this type of problem can best be prevented by increased emphasis on proper compaction and mix design. Remedial work on the present projects should be directed toward a seal coat application. Strip ravelled projects were found to have similar pavement properties in ravel and non-ravel led sections and general to be within desirable limits. Lower strength in resilient modulus tests and physically observed asphalt stripping in the ravelled sections indicate a localized failure of the asphalt aggregate bond. The failure occurrence in narrow longitudinal strips indicates a cause associated with paving operations--possibly differential compaction or hydrocarbon contamination. Preventive measures should ensure uniform compaction and more thorough checking of stripping tendencies. Corrective measures will require continued patching and possibly removal and replacement of affected pavement.

Authors:
Gietz,R. H.

Keywords:
aggregate, asphalt, asphalt concrete, asphalt pavement, compaction, concrete, condition, construction, construction methods, contamination, design, Distress, investigaton, overlay, pavement, resilient modulus, sampling, season, strength, tests, traffic, winter

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Abstract:
Criteria for selecting statewide monitoring sites for highway runoff were established t o provide representative combinations of climate, traffic highway, land use, geographic and topographic characteristics , Using thesecriteria , a minimum of six sites - were recommended for use to this research.

Authors:
Aye,Robert C.

Keywords:
criteria, highway, highway runoff, land use, land-use, monitoring, research, runoff, traffic, Water Pollutants, Washington State Monitoring

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Abstract:
A series of measurements was undertaken in the summer and fall of 1977 to determine the noise radiated by a wide variety of cars and trucks, and the effect of an acoustic wall, or barrier, on suppressing the transmission of that noise. The assumption of the \"correct\" effective radiating height was found to be the most critical parameter in making the calculations agree with the measured results. The \"best height\" value varied greatly from vehicle to vehicle, and with speed, load, and throttle setting for a given vehicle. The variability of this parameter made it impossible (solely from these tests) to assess such considerations as whether Fresnel\'s or Maekawa\'s curves should be used to calculate the attenuation produced by the wall.The most noteworthy observation from this study is that newer trucks not only are quieter (to meet noise radiation standards) but have an effective radiating height as low as 2 ft compared to as much as 11 ft for older trucks. \'Thus, as the newer types of trucks become predominant in the highway traffic mix, the effectiveness of walls and barriers in shielding the community from noise will increase considerably.This is good news, because wall effectiveness has been marginal at best for pre-1970 trucks because of their radiation heights.

Authors:
Foss,R. N.

Keywords:
attenuation, barrier, barriers, effectiveness, Fresenel diffraction, highway, Highway acoustics, noise, noise screens, Noise supression, speed, tests, traffic, truck, trucks, vehicle noise, walls

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Abstract:
Experimental data indicate that the combined effects of wind shear and ground plane attenuation can have a strong influence on sound propagation near the ground even at distances as short as 100 ft, The effectmanifests itself experimentally as a noticeable difference between sound propagation upwind vis-8-vis downwind that becomes more pronounced with either increased distance or increased wind speed. Differences of up to 25 dBA were found between into-the-wind and with-the-wind propagation fora listening height of 4 ft and a transmission distance of about 300 ft. Even a very moderate wind (4 mph) produced a difference of 12 dB at 150 ft for the same listening height. A large body of spectral data was also taken under a variety of wind conditions for path lengths of 150 ft and 225 ft. The resulting spectra agreed reasonably well with theoretical predictions for frequencies below 500 Hz, where ground and surface waves predominate; an important observation is that these waves were not affected substantially by wind conditions. Above approximately 500 Hz, the attenuation was frequently more than that predicted theoretically, and it was wind sensitive. The effect of wind was, in many cases, large, and could well mean that much experimentally obtained highway noise data is considerably less useful than previously thought, unless wind shear was taken into account during the measurements. In general, to "hear" the full effect of existing traffic, measurements should be made when the test positions downwind from the traffic.

Authors:
Foss,Rene N.

Keywords:
account, attenuation, condition, data, experimental, highway, Highway acoustics, ground plane attenuation, wind shear, interaction, noise, prediction, speed, traffic, wind

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Abstract:
As part of their continuing effort to prolong the life of existing pavement systems, highway engineers must continue to improve upon design and rehabilitation methods. In past years, design methods based upon empericism have been employed with considerable success. As loading and materials change or become more complex, the older practices become less useful and a new approach undertaken. Throughout the U.S. and elsewhere, there has been emerging new technology often termed " rational " , "systematic", "mechanistic", and other terms used to describe new approaches to pavement analysis and design. Mostof these are based on elastic or viscoelastic layered representation of the pavement structure and have the potential to become powerful tools for the highway engineer. In recent years, the University of Washington has assisted the Washington State Highway Department on various research projects . One project resulted in a report that has been used to develop guidelines for allowable truck traffic through the concept of pavement damage and/or remaining life . The basis forth is report was the concept that pavement structures can be reasonably well represented by elastic layered systems. Analysis of the mechanistic behavior can then be used to predict pavement response and l i f e expectancy. As a result of this study and after discussions with Highway Department personnel, it was determined that the procedures, techniques, as well as other information used in the above report may be of further interest to them. In other words, the methods as well as results had potential utilization in a wide range of applications . As a result , a seminar program was set up whereby the writer would conduct or lead weekly discussion sessions on key topics.

Authors:
Terrel,R. L.

Keywords:
analysis, applications, behavior, damage, design, highway, materials, mechanistic, pavement, pavement damage, program, rehabilitation, remaining life, research, seminar, structures, systems, technology, traffic, truck, Washington, Washington state

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Abstract:
At the request of the Washington State Department of Highways a study was conducted to evaluate three computer models specifically designed to predict carbon monoxide concentration at receptor points along roadways. The models were evaluated on their ability to predict values obtained from a monitoring network established along various roadways in the State of Washington. Monitoring consisted of 12 ground level CO stations, meteorological stations and traffic counters. Traffic speeds were sampled for conformity during peak hours. The final selected models, CALINE and EPA's HIWAY were given calibration factors to be used when calculating Receptor Concentrations for Impact Assessments.

Authors:
Badgley,Franklin, Rossana,T. August, Alsid,Hal F., Lutrick,David

Keywords:
air pollution, air quality, Assessment, calibration, carbon monoxide, computer, Computer Modelin, Concentrations, highway, Highways, impact, model, models, monitoring, quality, roadway, speed, traffic, Transportation Pollution Source, Washington, Washington state

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Abstract:
Evaluation of pavement patching materials was accomplished by simulating potholes in the surface, repairing the holes and subjecting them to traffic loadings. Loadings were applied utilizing the Pavement Test Facility, which applies truck simultaneously. Measurements of strength resulted in a comparative evaluation. tires was determined. Tire and various passenger car tire .types s skidding potential and pavement performance. Tread wear and protrusion of studs in the tires was determined.

Authors:
Cook,John C.

Keywords:
evaluation, facilities, materials, pavement, Pavement Patching Material, Polishing, Skidding Potential, Studded Tires, Garnet Impregnated Tires, pavement performance, performance, strength, studs, test track, tire, tires, traffic, truck

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Abstract:
This study was chiefly aimed at determining if a standard precast concrete median barrier placed on a highway shoulder in a fill section, would be effective in reducing highway traffic noise outside of the roadway prism. Secondly, it attacked the question of whether the current computer noise prediction program was giving accurate values.The first phase of the study consisted of collecting noise and traffic measurements in the field, first without and then with a median barrier, at two selected test sites. Next, the geometry of the test sites and field traffic data were entered into the computer program and the predicted noise levels obtained.The second phase consisted of comparing these two sets of data to determine the accuracy of the computer program and the amount of sound reduction, if any, due to the median barrier.The results indicated that the highway traffic noise was dominated by truck generated noise. It was therefore concluded that a standard median barrier will not provide a significant amount of sound reduction, outside of the roadway prism, when placed on a highway shoulder in a fill section. The results also indicated that the current computer noise prediction program will calculate noise levels that are usually higher than actually exist.

Authors:
Klasell,J. A., Butler,B. W.

Keywords:
Acoustical barrier, barrier attenuation, computer, computer program, concrete, data, ground attenuation, highway, median, median barrier, noise, Noise Levels, precast, precast concrete, prediction, program, research, roadway, traffic, traffic data, traffic noise, truck, wind, wind noise, barrier, project

Abstract:
Four different types of pavement marking materials were tested in Ring #6; three brands of striping paints and one thermoplastic stripping tape. These striping materials were applied on two sections, the ploymer ranked on the basis of appearance, wear, and whiteness.The thermoplastic striping material consistently outperformed the three paints. The materials wore more rapidly on the polymer cement concrete that on the asphalt concrete and the ranking order for the paints was different for the two sections. The Type #3 stud seemed to have worn the paints more rapidly than either #4, #2, GST, US and UST studs and tires in that order respectively. The superiority of the ethermoplastic striping tape was due to its thickness and its construction. Last year Kennametal, Inc. sent the Transportation Systems Section four different types of traffic paint and a thermoplastic striping tape. Time did not permit the testing of these materials in Ring #5, so these materials were tested in Ring # 6.

Authors:
Krukar,M.

Keywords:
asphalt, asphalt concrete, concrete, construction, effects, ITS, materials, pavement, Phase II, polymer, striping, striping paints, stripping, Studded, studded tire, studded tires, studs, System, systems, tire, tires, traffic, transportation

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Abstract:
In many parts of the world, the design of flexible pavement is still based on empirical methods which have developed from engineering experience. These empirical methods cannot be extrapolated beyond their limits without full scale trials to prove their applicability. In recent years, however, the increase of traffic, both in volume and axle loads, has led to the failure of many roads previously considered well designed. For this reason, therefore, researchers realized that a closer look at the pavement materials was desirable in order to develop a rational design procedure. Due to the complexity of characterizing pavement materials, and the limitations of instrumentation, much of the reported work offered little help in changing design practice. This is, perhaps, due to many simplifying assumptions which had to be introduced in the experimental procedure as well as the interpretation of the test results. Recently, however, there has been a sharp advancement in test instrumentation and an outstanding progress in processing the experimental results. This has been reflected through many fine investigations and has increased the demand for more improvements. An asphalt pavement is a complex structure whose function is to provide a suitable surface for a highway, an airport, or other off-highway facility. The load of a vehicle or an aircraft is transmitted through the multilayered system of processed materials which have different mechanical properties. The stress distribution within this system is highly complex and to a large extent is dependent on the relative stiffnesses of the individual layers.

Authors:
Terrel,Ronald L., Awad,S.

Keywords:
asphalt, asphalt pavement, axle, base, behavior, demand, design, developed, experimental, facilities, fine, highway, improvement, loads, materials, methods, pavement, stiffness, stresses, System, traffic, volume

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