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

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

Keywords:
Congestion, incident-induced delay, short-term traffic flow forecast

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Abstract:
Traffic incidents cause approximately 50 percent of freeway congestion in metropolitan areas, resulting in extra travel time and fuel cost. Quantifying incident-induced delay (IID) will help people better understand the real costs of incidents, maximize the benefit-to-cost-ratio of investments in incident remedy actions, and facilitate the development of active traffic management and integrated corridor management strategies. Currently, a number of algorithms are available for IID quantification. However, these algorithms were developed with certain theoretical assumptions that are difficult to meet in real-world applications. Furthermore, they have only been applied to simulated cases and have not been sufficiently verified with ground-truth data. To quantify IID over a regional freeway network using existing traffic sensor measurements, a new approach for IID estimation was developed in this study. This new approach combines a modified deterministic queuing diagram with short-term traffic flow forecasting techniques to overcome the limitation of the zero vehicle-length assumption in the traditional deterministic queuing theory. A remarkable advantage with this new approach over most other methods is that it uses only volume data from traffic detectors to compute IID and hence is easy to apply. Verification with the video-extracted ground truth IID data found that the IID estimation errors with the new approach were within 6 percent for the two incident cases studied. This implies that the new approach is capable of producing fairly accurate freeway IID estimates using volumes measured by existing traffic sensors. This approach has been implemented on a regional map-based platform to enable quick, convenient, and reliable freeway IID estimates in the Puget Sound region.

Authors:
Wang, Y., Yu, R., Lao, Y., Thomson, T.

Keywords:
Congestion, incident-induced delay, short-term traffic flow forecast

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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:
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:
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:
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 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. This report details the findings for the SWIFT Consumer Acceptance Study based on the evaluation objectives that were identified in the SWIFT Evaluation Plan (1995). The primary objectives of the SWIFT Consumer Acceptance Study were to assess the following: Importance of traveler information in travel planning, Usefulness of SWIFT traveler information in travel planning, Minimum set of user services and device features required to provide viable product and services, User perceptions of SWIFT device usefulness, Willingness-to-pay for different services. User perceptions of changes in travel convenience and efficiency, User perceptions of changes in traffic congestion, air quality, energy consumption, and safety. ,

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 is a summary of the results of Phase I for this project. It recommends a two-tiered congestion monitoring system for use in the state of Washington. In uncongested areas of the state it recommends use of volume/capacity ratios to estimate congestion levels. For congested roads, travel time measures are recommended. In addition to these measures, additional data items (mode choice, vehicle volumes, average vehicle occupancy, etc.) are also needed to measure congestion.

Authors:
Hallenbeck,M. E.

Keywords:
transportation management, congestion, congestion monitoring, congestion management systems, performance monitoring, traffic monitoring, ISTEA management systems

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Abstract:
This report provides detail on the options for monitoring traffic congestion within the state of Washington. It refines initial estimates of straffing and equipment resource needs for the data collection systems analyzed. This document also answers questions raised by the recommendations made in the Phase1 report for this project. Finally, this report provides specific recommendations for near-term actions the Washington State Department of Transportation (WSDOT) can take towards providing a cost-effective congestion monitoring system for the state's urban areas.

Authors:
Hallenbeck,M. E.

Keywords:
congestion, congestion monitoring, performance monitoring, ISTEA management systems

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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, transportation, survey, neighborhood, linkage, land use, policy, travel behavior, development, walking, traffic, congestion

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Abstract:
This report summarizes describes a research project that used computer simulations to explore potential solutions to the growing congestion problems on one for the Puget Sound region\'s major commute routes. SR 520 is one of he region\'s most congested freeways; slowdowns on this corridor adversely affect traffic on connecting freeways such as I-405 and I-5. This project explored two linked, no-build options: ramp metering only, on the om-ramps of SR 520, and ramp metering plus HOV bypass lanes. Computer simulation revealed that metering ramps onto SR 520 would improve he mainline traffic flow However, the simulation also predicted that it would create long queues at the metered ramps, for both single-occupancy vehicles (SOVs) and high-occupancy vehicles (HOVs). Given the HOV orientation of this project, an effort was made to give HOVs delay-free access to the improved mainline flow. For this purpose, HOV bypass lanes on the metered ramps were simulated. Model output indicated that bypass lanes would, in fact, give HOVs a clear time advantage over SOVs without degrading mainline flows or significantly worsening ramp delays for SOVs.

Authors:
Chang, J., McCormack, E.D., Rutherford, G.S., Ishimaru, J.M.

Keywords:
Ramp metering, high-occupancy vehicle, HOV bypass, congestion, simulation

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Abstract:
In this initial study, the researchers concentrated their year-long (1991-1992) data collection and evaluation efforts on both the I-5 North 2+ Demonstration and the I-5 South Interim Project. The data were collected by field observations, WSDOT detector systems, and traveler opinion surveys. The Washington State Patrol, WSDOT, King County Metro, Pierce Transit, Community Transit, and the Texas Transportation Institute all provided relevant information and assistance.

Authors:
Ulberg, C., Farnsworth, G.

Keywords:
High occupancy vehicle, HOV, monitoring, average vehicle occupancy, congestion, enforcement

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Abstract:
This study analyzes the impacts of the Goodwill Games on traffic congestion in the Seattle-Tacoma metropolitan corridor. The study concentrates on the combined impacts of increased traffic volumes resulting from Goodwill Games events, and the traffic mitigation measures designed to relieve the congestion resulting from those events. The study emphasis is on traffic congestion near the largest venues, Husky Stadium, Cheney Stadium, the Tacoma Dome, and the Seattle Center. The study considers traffic volume, traffic speed, incident response, and transit ridership data from a number of sources. The basic conclusion of the report are that in most cases the increased traffic expected for the Goodwill Games and the savings from measures implemented to mitigate those volume increases balanced each other. The result was that traffic conditions remained fairly normal throughout the Games. In some instances, traffic improved (for example, on many days peak period traffic speeds increased on SR-520), and in other instances, particularly when incidents occurred during peak travel periods, traffic conditions were worse than normal. However, average traffic conditions changed little during the Games.

Authors:
Hallenbeck, M.E.

Keywords:
Traffic surveillance and control, congestion, events, incident response

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Abstract:
Problems of forecasting freeway traffic variables a few minutes in advance, particularly lane occupancy and the difference between in flowing and outflowing traffic for a short section of freeway, are explored. Methods based on linear time series analysis were found to do reasonably well at forecasting mean values but not so well for those extremes corresponding to the onset of congestion. Techniques based on statistical pattern recognition principles were found to be promising. The most promising of the pattern recognition algorithms was put into use on a section of I-5 and is being field tested.

Authors:
Davis, G.A., Nihan, N.L., Hamed, M.H., Jacobson, L.N.

Keywords:
Congestion, forecasting, pattern recognition

External Links: https://onlinepubs.trb.org/Onlinepubs/trr/1990/1287/1287-004.pdf

Abstract:
This paper discusses the application of the CORFLO model by the Washington State Department of Transportation for examining traffic congestion related to urban freeway reconstruction efforts. The model is being used to estimate congestion levels expected as a result of capacity restraints imposed by construction activities and to examine the impacts of alternative traffic mitigation plans on those expected congestion levels. This report documents the Department\'s calibration effort, the initial tests of the model\'s capabilities, the conclusions and recommendations that resulted from those tests, and a plan for the continuation of the research effort under this contract.

Authors:
Rickman, T., Rutherford, G.S., Hallenbeck, M.E., Jacobson, L.N.

Keywords:
TRAF , simulation model, CORFLO model, evaluation, congestion

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