Abstract:
The design of HOV lanes and other HOV facilities depends on volumes of HOV's expected to use the facilities. Currently, there is no good method for predicting vehicle occupancy on specific highway facilities. The basic objective of this research was to incorporate the best previous transportation models with new information on psychological and demographic determinants of mode choice into a model that forecasts vehicle occupancy for specific highway facilities. In order to do this, four different data sets were investigated. Each one allowed us to investigate one or more aspects of a comprehensive model to forecast vehicle occupancy. The basic approach tested in this research was the 'integrated model of a consumer choice,' first proposed by Tybout and Hauser in 1981. It incorporates a wide variety of factors involved in transportation decision-making. Most of the findings from the four data sets analyzed for this study were consistent with the literature and with each other. The research concluded that, in order for transportation model to adequately forecast vehicle occupancy, it should take into account that 1) mode choice changes over time, 2) attitudes and perceptions are important in mode choice, 3) attitudes and perceptions can be influenced by experience, 4) household composition is important, 5) commute length varies by type of job and location, 6) constraints influence the process in complicated ways, and 7) two person carpools are different from larger carpools. The dynamic aspects of mode choice are critical to understand. Until we have more good time series data and the ability to adequately understand it, our models of mode choice and vehicle occupancy will be deficient.

Authors:
Ulberg,C.

Keywords:
traffic surveillance and control, vehicle occupancy, transportation model, transportation surverys, panel data, HOV facilities

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Abstract:
To mitigate increasing traffic congestion and to improve highway safety, state departments of transportation have come up with some innovative strategies for optimizing the efficiency of congested freeway sections. Two such strategies are freeway-to-freeway ramp metering and mainline metering. Freeway-to-freeway ramp metering involves installing traffic signals (either on their side of the roadway or overhead) on the ramps found at freeway-to-freeway interchanges. Mainline metering involves installing traffic signals (usually overhead) on the mainline of a freeway. This paper examines some examples of freeway-to-freeway ramp metering in the United States, namely, in Minnesota and California. The advantages and disadvantages of freeway-to-freeway ramp metering are discussed. This paper then describes the only known operating example of mainline metering in the United States. Implementation and operational issues of mainline metering are discussed. The paper suggests that a complete and thorough analysis should take place prior to the installation of any freeway-to-freeway or mainline metering system. This analysis is needed to ensure that safety is maintained and that environmental concerns are addressed. The suggested policy on freeway-to-freeway ramp metering is as follows: 'Install meters on freeway-to-freeway ramps where system performance and efficiency will be improved.' The suggested policy on mainline metering is as follows: 'Install mainline meters on freeways approaching bottleneck locations where analysis indicates that improved traffic operations will result.' Guidelines for both metering types are listed in the paper.

Authors:
Klastorin,T., Pivo,G., Pilcher,M., Carlson,D., Hyman,C., Hansen,S., Hess,P., Thatte,A.

Keywords:
traffic surveillance and control, traffic congestion, ramp metering, TRB

Abstract:
This study describes the analysis of truck volume data collected by the Washington State Department of Transportation (WSDOT) over four and one half years, from 1988 through 1993. The primary objectives of this research were to: investigate the patterns in truck volumes at various locations in Washington State; determine whether seasonal factors can be developed and applied to short-duration truck volume measurements to better estimate average annual conditions; develop an easy procedure that other states can use to create their own seasonal factoring process, and produce a guidebook that explains this process and lists the necessary steps and concisely. This report summarizes all but the last of these objectives. This last objective is met in another summary report.

Authors:
Hallenbeck,M. E., Kim,S.

Keywords:
traffic surveillance and control, transport, weight, pavement management systems, truck counts, traffic counting

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Abstract:
Traffic congestion is an increasing problem in many areas of Washington State. Efforts to control traffic flows and mitigate congestion must rely on the ability to accurately monitor the state of traffic flow on highways and arterials. This project, sponsored by WSDOT and executed at the University of Washington, combines two important aspects of geodesy, geographical information systems (GIS) and the global positioning system (GPS), to produce a traveler information system. This project produced a computer application that draws a graphical representation of the transportation data (a map) on an X-terminal. This project also produced a second computer application to perform real-time vehicle positioning using GPS. These two applications operate in a client/server paradigm is used to combine location and congestion information on one, digitally generated map display.

Authors:
Dailey,D. J., Lin,P.

Keywords:
traffic surveillance and control, GPS, GIS, traveler information, maximum likelihood, digital maps, distributed computing, client server

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Abstract:
This paper 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 with inductance loop data gathered on Interstate Five in Seattle, Washington. It discusses the scaling of thresholds necessary for anomaly detection but does not provide specific threshold values. This technique of dynamic prediction used with thresholds could have potential value to traffic management systems that rely heavily on inductance loop data.

Authors:
Dailey,D. J.

Keywords:
traveler information, ITS backbone, distributed computing, client server model, ITS architecture, speed estimates, volume, occupancy, traffic surveillance and control, inductance loop data, traffic management systems, TRB

Abstract:
This report presents the results of an evaluation of a prototype automatic vehicle identification (AVI) system. AVI can identify and locate specific vehicles at a precise location. We chose to investigate a loop-based AVI systems, primarily because the Puget Sound area freeway system has numerous inductive loop detectors already in place, and we expected that the current method of collecting traffic could be augmented by an AVI system. However, before implementing any large-scale AVI system, we first wanted to test a small scale, prototype system based on technology that 'piggy backs' AVI detectors on existing loop detectors. The tests revealed a failure to detect buses at the rate of nearly on-in-five expected detections. While the exact cause or causes of the failures are not completely clear, we suspect the loop system itself to have been the prime contributor to the failures. We recommend further testing and troubleshooting to help determine the viability of the AVI system. We also recommend implementing and testing a method for remote access of AVI data. Assuming that the technical difficulties can be solved (or that a nearly on-in-five detection error rate is acceptable), there are potential applications of loop-based AVI technology in the Puget Sound region. These include (1) performance monitoring of HOV lanes, (2) regulation of HOV lane use, (3) real-time location data for advanced public transportation systems, and (4) transit fleet management.

Authors:
Butterfield,E., Haselkorn,M., Alalusi,K.

Keywords:
traffic surveillance and control, automatic vehicle identification, AVI, advanced public transportation system, IVHS

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Abstract:
This report summarizes the methodology used by the Washington State Transportation Center in fulfillment of the requirements for the Washington State Department of Transportation grant 'HOV Lane Evaluation and Monitoring Tool.' This report describes the types of data collected, how the data was collected, and the uses of the data. The report then makes some preliminary findings based on the analysis to date. Designing a system for evaluating the performance of high occupancy vehicle lanes includes establishing methods for collection and analysis of vehicle occupancy, travel time, and public opinion data. Secondary sources include data on enforcement of HOV lane restrictions, accidents, and transit ridership. The objective of this report is to identify the most effective and efficient method for collecting and analyzing the required data. Issues addressed in identifying the most appropriate methodology included the following: selecting data collection sites, developing a computer program to facilitate data collection and storage, management of traffic observers, scheduling, developing computer programs for auditing and analyzing data, developing a system for mailing public opinion surveys to commuters observed in the field, and analysis of the public opinion data. It is important to note that this report concerns the development of a methodology and is not designed to be an authoritative analysis of the effectiveness of high occupancy vehicle lanes. The analysis of the data described in this report will be published in a forthcoming report for the companion project, 'HOV Lane Evaluation and Monitoring.'

Authors:
Benuska,M., Hansen,M., Ulberg,C.

Keywords:
traffic surveillance and control, HOV lane evaluation, traffic observation

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Abstract:
This study evaluated various high occupancy vehicle (HOV) lane enforcement techniques on a recently constructed section of HOV lanes along I-405 in the Seattle, Washington, area. The research included a related public opinion survey concerning HOV lanes. The enforcement techniques that were evaluated included intensive (or continuous saturation) enforcement, once a week saturation enforcement, and once a week stationary enforcement. This study concluded that each type of enforcement effort helped in lowering the number of HOV lane violations; however, it was not possible to determine which method was most effective. Violations decreased considerably during the first weeks of enforcement, regardless of the type of enforcement. The public opinion survey indicated that, in general, the public supports the concept of HOV lanes. Eighty-six percent of the respondents felt that HOV lanes are a good ides. At the same time, 55 percent indicated that existing HOV lanes were not being used enough. Almost 60 percent of the respondents believed HOV lane violators were seldom caught by enforcement agencies. A higher percentage of the respondents (71 percent) believed that HOV violations increased when the Washington State Patrol was not visible along the HOV lane. The research team recommends intensive enforcement only for the first three months (or less) of the operation of a new HOV facility. After that point, the level of effort should revert to routine enforcement. This study also makes recommendations concerning the design of HOV lanes as it is relates to enforcement issues. Specifically, enforcement areas alongside HOV lanes must be designed in cooperation with the appropriate enforcement agency. Two types of enforcement areas along freeways are suggested.

Authors:
Ulberg,C., Jacobson,E. L.

Keywords:
traffic surveillance and control, HOV, high occupancy vehicle, enforcement, public opinion, HOV enforcement, HOV lane design

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Abstract:
See 65-0951 for description. This was a joint effort with TransNow.

Authors:
Ulberg,C.

Keywords:
traffic surveillance and control, mode choice, HOV, TDM

Abstract:
The major objective of this project was to develop a post-earthquake emergency response plan to WSDOT bridge management. Three types of seismic events was considered in the development of the plan. Inspection forms were developed for the three-stage inspection process. For events other than minor earthquakes under favorable weather and lighting conditions, existing resources appear to be inadequate. Recommendations for improving the readiness of the WSDOT bridge management are provided.

Authors:
Reed,D., Wang,J.

Keywords:
traffic surveillance and control, earthquake, emergency response planning, bridge

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Abstract:
This paper will discuss the problems that are inherent with adding a higher speed HOV lane to an arterial with its unlimited access points. Investigation of current literature will show that although freeway HOV applications have been researched and understood to an adequate degree, almost no data of any kind is available to predict the effectiveness of an arterial HOV project. Further, it will be proposed that not only does the research not exist, but that the 'measures of effectiveness' to evaluate existing arterial HOV lanes are severely lacking. In addition to the literature search, a motorist survey was handed out to collect data describing commute trip behavior. Questions about trip origin, destination, and purpose were asked to determine what residential and commercial zones were being served by N.E. 85th/Redmond Way, and for what purpose. The questionnaire also requested information on the duration of the trip and the occupancy of the vehicle. This data was used as input for a mathematical model to predict the volumes on the facility one year after the implementation of an HOV lane. The fact that the model was based on past freeway applications across the nation, and the threats to validity that causes, will also be presented. The final questions on the survey concerned the motorists' own prediction about how likely they were to carpool and what they thought were some of the problems preventing them. These views will be compared with the results from the model. The predictions and resulting effectiveness of the project will be evaluated versus the stated objectives of the Eastside Transportation Program (ETP) policy statement.

Authors:
Nihan,N. L., Rubstello,L. O.

Keywords:
traffic surveillance and control, arterial HOV, HOV, high occupancy vehicle

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Abstract:
The current project addressed two major weak points of the existing WSDOT Ramp Control System. One weak point in the system is the fact that it reacts to the problem (congestion), rather than preventing the problem. The other weak point in the system is its reliance on detector data that may be in error. Both of these problems can be minimized by developing methods to accurately predict short-term traffic data. By predicting the onset of congestion early enough, the ramp metering system can act to prevent or delay occurrence of the problem. Also, if a detector has failed or is malfunctioning, the data from the detector can be estimated from short-term predictions based on neighboring detectors. At the beginning of the current project, the researchers had hoped that the same model would provide a basis for both forecasting congestion (for predictive ramp control) and replacing erroneous data (predicting actual values). However, the best method for filling in missing detector data turned out to be multivariate time series analysis. Several pattern recognition and time series models were tested for further development. In both cases, the simpler models turned out to be the best choices, and in both cases, further model testing and development were recommended. The research on both model types continues in follow-up studies that are expected to lead to incorporation of these models in the new TSMC computer system.

Authors:
Nihan,N. L., Knutson,K. L.

Keywords:
bridge and construction, turner proposal, concrete bridge, fatigue, overload, replacement costs, remaining life, route assessment, maximum moments, maintenance, design loads, continuity, traffic surveillance and control, ramp controls, freeway management, traffic flow forecasts, forecast models, ramp metering

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Abstract:
The primary objectives for this study were to investigate state-of-the-art techniques for providing HOV incentives on arterial routes.The primary goal of making HOV improvements has been to increase the efficiency of transportation systems. Secondary objectives have been to reduce energy consumption, improve air quality, increase modal shift, save travel time, and reduce congestions. Reviews of existing facilities have synthesized operational results into useful generalizations. HOV facility issues include safety, enforcement, planning/design guidelines, classification schemes, and performance measures. Arterial HOV improvements have had mixed success, though the lack of good before-and-after studies is significant. HOV facilities have been studied with a variety of computer models. In system analysis, HOV lanes may be better justified as people movers when they are compared with other fixed-transit alternatives than when they are compared with automobile traffic in adjacent, nonrestricted lanes.During the coming decade the HOV system will continue to expand. This project has an opprotunity to contribute significantly to the understanding of the techniques and potentials for arterial HOV improvements. The first step, a review of the existing literature, establishes a basis for the research to follow.

Authors:
Nihan,N. L., Davis,J. E.

Keywords:
traffic surveillance and control, arterial HOV, HOV, high occupancy vehicle

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Abstract:
The main research objective of this study is to improve the limitations on arterial traffic simulation models TRAF-NETSIM and TRANSYT-7F so that they can be used to overcome the above HOV lane planing deficiencies. For instance, after integrating the improved traffic operation models, the evaluation methods can be more adequate for consideration of complex variables associated with arterial HOV lanes. The traffic impacts of HOV lanes can be analyzed from these improved traffic models; therefore, the relationship between traffic impacts and mode shift behavior can be modeled more accurately. Finally, the guidelines to install a successful HOV lane can be derived according to the results of HOV lane evaluation. In brief, the objectives of this study are to: 1. Modify the logic of TRAF-NETSIM turning movements for simulating arterial HOV lanes realistically. 2. Modify the calculation algorithms of TRAF-NETSIM link statistics to provide the travel time of each vehicle type for HOV lane evaluation. 3. Develop the smoothing factor analytical method for TRANSYT traffic platoon dispersion model so that this model can be enhanced and applied appropriately in mixed-flow and priority lane traffic analysis. 4. Develop two iteration algorithms for TRANSYT traffic platoon prediction so that this model can simulate congested flow accurately. The scope of this study is limited to focus on the planning process of arterial concurrent flow HOV lanes using traffic simulation models TRAF-NETSIM and TRANSYT-7F.

Authors:
Nihan,N. L., Chen,H.

Keywords:
traffic surveillance and control, arterial HOV, HOV, high occupancy vehicle

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Abstract:
The current project addressed two major weak points of the existing WSDOT Ramp Control System. One weak point in the system is the fact that it reacts to the problem (congestion), rather than preventing the problem. The other weak point in the system is its reliance on detector data that may be in error. Both of these problems can be minimized by developing methods to accurately predict short-term traffic data. By predicting the onset of congestion early enough, the ramp metering system can act to prevent or delay occurrence of the problem. Also, if a detector has failed or is malfunctioning, the data from the detector can be estimated from short-term predictions based on neighboring detectors. At the beginning of the current project, the researchers had hoped that the same model would provide a basis for both forecasting congestion (for predictive ramp control) and replacing erroneous data (predicting actual values). However, the best method for filling in missing detector data turned out to be multivariate time series analysis. Several pattern recognition and time series models were tested for further development. In both cases, the simpler models turned out to be the best choices, and in both cases, further model testing and development were recommended. The research on both model types continues in follow-up studies that are expected to lead to incorporation of these models in the new TSMC computer system.

Authors:
Nihan,N. L., Cabrera-Gonzalez,I.

Keywords:
bridge and construction, turner proposal, concrete bridge, fatigue, overload, replacement costs, remaining life, route assessment, maximum moments, maintenance, design loads, continuity, traffic surveillance and control, ramp controls, freeway management, traffic flow forecasts, forecast models, ramp metering

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Abstract:
The current project addressed two major weak points of the existing WSDOT Ramp Control System. One weak point in the system is the fact that it reacts to the problem (congestion), rather than preventing the problem. The other weak point in the system is its reliance on detector data that may be in error. Both of these problems can be minimized by developing methods to accurately predict short-term traffic data. By predicting the onset of congestion early enough, the ramp metering system can act to prevent or delay occurrence of the problem. Also, if a detector has failed or is malfunctioning, the data from the detector can be estimated from short-term predictions based on neighboring detectors. At the beginning of the current project, the researchers had hoped that the same model would provide a basis for both forecasting congestion (for predictive ramp control) and replacing erroneous data (predicting actual values). However, the best method for filling in missing detector data turned out to be multivariate time series analysis. Several pattern recognition and time series models were tested for further development. In both cases, the simpler models turned out to be the best choices, and in both cases, further model testing and development were recommended. The research on both model types continues in follow-up studies that are expected to lead to incorporation of these models in the new TSMC computer system.

Authors:
Nihan,N. L., Babla,M. D.

Keywords:
bridge and construction, turner proposal, concrete bridge, fatigue, overload, replacement costs, remaining life, route assessment, maximum moments, maintenance, design loads, continuity, traffic surveillance and control, ramp controls, freeway management, traffic flow forecasts, forecast models, ramp metering

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Abstract:
This report presents an analysis of HOV Improvements for two signalized arterials in the Seattle metropolitan area. The first involves a planned 1,000 foot queue jumper lane on NE Pacific Street in the University District of Seattle. This planned improvement was studied prior to its implementation in Spring of 1990. As part of the study, an extensive before-data set was developed. The planned improvement is now in place,and an extensive after-study is now in progress as part of a follow-up project. The second study was more of a feasibility analysis of possible HOV improvements for a suburban arterial. Specifically, NE 85th/Redmond Way, an arterial that stretches 2.5 miles, from Interstate 405 in Kirkland to Willows Road in Redmond, was identified as one of the highest priority candidates for arterial HOV improvements. Because of limited arterial HOV experience in Seattle and nationwide, the study of these two very different types of HOV arterial improvements provided important information for future arterial plans. This project investigated HOV improvements for arterials in the Seattle area, simulated the operation of those improvements for the two case studies, developed a data set for evaluating the impacts of the improvements, and carried out some preliminary evaluations. The preliminary findings of these two case studies suggested favorable outcomes for the planned HOV improvements. Keeping in mind that these analyses must be evaluated in the context of the surrounding network, the results of these two case studies are optimistic.

Authors:
Nihan,N. L.

Keywords:
traffic surveillance and control, arterial HOV, HOV, high occupancy vehicle

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Abstract:
This report details the research involved in developing the Emergency Response Guide for Highway Maintenance Managers. The Emergency Response Guide for Highway Maintenance Managers details WSDOT\'s emergency management procedures and describes how managers should respond to and handle emergencies resulting from natural or technological disasters that impact the transportation system and associated physical plants. The guide further describes WSDOT\'s emergency related organizational roles and responsibilities. This report describes the information contained in each section of the guide, identifies the sources of the information, and outlines the procedures the authors used to obtain the information. This report also contains recommendations for improving WSDOT\'s emergency preparedness.

Authors:
Mannering,F. L., Louie,M., Reed,D.

Keywords:
traffic surveillance and control, emergency response, emergency preparedness, disaster response

Abstract:
This report details the research involved in developing the Emergency Response Guide for Highway Maintenance Managers. The Emergency Response Guide for Highway Maintenance Managers details WSDOT's emergency management procedures and describes how managers should respond to and handle emergencies resulting from natural or technological disasters that impact the transportation system and associated physical plants. The guide further describes WSDOT's emergency related organizational roles and responsibilities. This report describes the information contained in each section of the guide, identifies the sources of the information, and outlines the procedures the authors used to obtain the information. This report also contains recommendations for improving WSDOT's emergency preparedness.

Authors:
Mannering,F. L., Louie,M.

Keywords:
traffic surveillance and control, emergency response, emergency preparedness, disaster response

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Abstract:
A computer system was developed to integrate three pre-existing traffic control systems. These three systems were the traffic signal systems on SR-99 and SR 522 in northern King County and the freeway ramp metering system (FLOW System) on Interstate 5 north of the Seattle central business district. This project continued previous WSDOT research, described in the report 'Arterial Control and Integration, Final Report,' March 1990. The integration system developed in this effort consisted off a single microcomputer that communicated with both the mini-computer that operated the FLOW system and the microcomputer through which an operator controlled both arterial signal networks. To minimize development effort and costs and to demonstrate the potential for adding integration capabilities to traffic control systems, the integration system relied extensively on the control system's existing capabilities. Tests of the integration system produced mixed results. The basic system design was flexible and met the needs described in the earlier WSDOT report. The control system also showed that it can use the data collected by one control system and adjust the control strategy of another, independent system. Unfortunately, the integration system was not a complete success and therefore was not implemented by WSDOT. The integration system suffered from unreliable inter-computer communications. The communications difficulties were caused by 'off-the-shelf' computer networking software that was not sufficiently fault tolerant for real-time control system applications. That is, the integration system experienced intermittent communications failures between the control system computers. These failures disrupted system operation, and that disruption could have significantly degraded traffic operations. A system operator was able to easily fix the communications failures, but the integration computer could not automatically handle them.

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

Keywords:
traffic surveillance and control, traffic control systems, traffic control integration, ATMS, advanced traffic management systems

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Abstract:
A computer system was developed to integrate three pre-existing traffic control systems. These three systems were the traffic signal systems on SR-99 and SR 522 in northern King County and the freeway ramp metering system (FLOW System) on Interstate 5 north of the Seattle central business district. This project continued previous WSDOT research, described in the report 'Arterial Control and Integration, Final Report,' March 1990. The integration system developed in this effort consisted off a single microcomputer that communicated with both the mini-computer that operated the FLOW system and the microcomputer through which an operator controlled both arterial signal networks. To minimize development effort and costs and to demonstrate the potential for adding integration capabilities to traffic control systems, the integration system relied extensively on the control system's existing capabilities. Tests of the integration system produced mixed results. The basic system design was flexible and met the needs described in the earlier WSDOT report. The control system also showed that it can use the data collected by one control system and adjust the control strategy of another, independent system. Unfortunately, the integration system was not a complete success and therefore was not implemented by WSDOT. The integration system suffered from unreliable inter-computer communications. The communications difficulties were caused by 'off-the-shelf' computer networking software that was not sufficiently fault tolerant for real-time control system applications. That is, the integration system experienced intermittent communications failures between the control system computers. These failures disrupted system operation, and that disruption could have significantly degraded traffic operations. A system operator was able to easily fix the communications failures, but the integration computer could not automatically handle them.

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

Keywords:
traffic surveillance and control, traffic control systems, traffic control integration, ATMS, advanced traffic control management system

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Abstract:
The Washington State Department of Transportation has produced this guide to improve development of traffic forecasts used by the Department engineers and planners. The guide is intended to help standardize the methodology for developing forecasts, provide an 'audit trail' of steps and assumptions behind each forecast, and ensure that the assumptions underlying the forecasting process have been carefully considered. The guide is split into two volumes. The first volume describes the forecasting process and reviews the issues that must be addressed. The second volume provides detailed instructions for the forecasting process. Volume 1 contains background information on the steps involved in forecasting and the factors that must be considered as part of a traffic forecast. It should be used to introduce staff to the traffic forecasting process. It will also help identify the resources required to forecast traffic and then assist in analyzing and applying those resources. Volume 2 of the guide contains a more precise description of how to perform the forecast. In addition, the Volume 2 appendices contain copies of the worksheets that should accompany any forecasts engineers perform and instructions on using several Lotus 1-2-3 spreadsheets that were designed to ease the forecasting process. Lastly, Volume 2 contains a copy of the Lotus 1-2-3 templates for use by engineers and planners.

Authors:
Hallenbeck,M. E.

Keywords:
traffic surveillance and control, traffic forecasting, forecasting, transportation planning

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Abstract:
The Real Time Motorist Information System (RTMIS) under development at the University of Washington uses a ratio of Volume to Occupancy with a correction factor (often denoted as 'g') to estimate speed. This correction factor is a function of road topology and occupancy. This project will initially produce a value for the correction factor for every pair of loops being used in the RTMIS. It will further produce a correlation between correction factor and occupancy for each set of loop pairs. The correction factor is produced using speed estimates from cross-correlation time delay measurements of on road data.The Real Time Motorist Information System (RTMIS) under development at the University of Washington uses a ratio of Volume to Occupancy with a correction factor (often denoted as 'g') to estimate speed. This correction factor is a function of road topology and occupancy. This project will initially produce a value for the correction factor for every pair of loops being used in the RTMIS. It will further produce a correlation between correction factor and occupancy for each set of loop pairs. The correction factor is produced using speed estimates from cross-correlation time delay measurements of on road data.

Authors:
Dailey,D. J., Haselkorn,M., Nihan,N. L.

Keywords:
traffic surveillance and control, induction loops, speed cross correlation, volume occupancy

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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:
This project developed a prototype computer-aided vessel log system of the Washington State Ferry System (WSF). The researchers generated three reports that describe the results of their research. This first volume contains a description of the project and summarizes the design and testing results of the prototype automated vessel log. The second volume contains a two-part guide that describes that prototype software program in details. Part One of this second volume was written for technical administrators who must understand the programs' production to enable them to direct refinement of the prototype. Part Two of the second volume was written for the programmers who will develop the code refinements. The second volume also contains the source code listings for all this project's programs. The third volume contains a user's guide to the program. A diskette containing all of the program's source code and the executable programs has been sent to the WSF Service Planning Manager at Colman Dock.,TRAC/University of Washington

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

Keywords:
traffic surveillance and control, marine, ferry operations, vessel logbooks

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Abstract:
This project developed a prototype computer aided vessel log system for the Washington State Ferry System (WSF). The Researchers generated three reports that describe the results of their research. This report, which is the second volume of three, contains a two-part guide that describes that prototype software program in detail. Part One of this second volume was written for technical administrators who must understand the program's production to enable them to direct refinement of the prototype. Part Two of this volume was written for the programmers who will develop the code refinements. This volume also contains the source code listings for all of this project's programs. The other two volumes are a summary report for the project and a user's guide. The first volume (the summary report) contains a description of the project and summarizes the design and testing results of the prototype automated vessel log. The third volume contains a user's guide for the prototype software. A diskette containing all of the program's source code and the executable programs has been sent to the WSF Service Planning Manager at Colman Dock.

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

Keywords:
traffic surveillance and control, marine, ferry operations, vessel logbooks

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Abstract:
Transportation demand management (TDM) has received increasing attention in recent years as an important component in approaches to improving the transportation system. Another approach to transportation system improvement is the use of high occupancy vehicle (HOV) facilities. Mode choice forecasts provide the basis for planning, project evaluation, and obtaining public support for TDM measures and improvements to the HOV system. Despite the importance of accurate mode forecasts, current mode choice methodology is insufficiently responsive to factors that influence shifts to ridesharing modes, particularly TDM policy factors that are important in encouraging commuters to shift form single occupant vehicles (SOVs). The objective of this study is to identify these mode choice factors and use them to improve the ability to analyze HOV policies for the north I-5 corridor. Two major sets of data were analyzed in this study, both collected by Metro in cooperation with Community Transit. In one study, some 9,324 employees of 23 cooperating businesses were surveyed in north King and urban Snohomish counties. In another, a 1989 telephone survey questioned a random sample of 3,586 residents in the study area. Several analytical approaches were used on this study, including multinomial logit modeling, factor analysis ad cluster analysis. Many of the findings from this study are important to understanding the nature of mode choice. Some of the results are important for policy recommendations. Some of the results indicate a different emphasis for employer-based TDM measures in a largely suburban area than in a major CBD such as Seattle or Bellevue. Study findings indicate the importance of (1) completing the HOV lane system, (2) providing workplace incentives for ridesharing, (3) taking the existence to two-worker households into account, (4) providing alternative ways for employees to run errands, (5) encouraging mixed use through flexible zoning laws, (6) providing non-motorized vehicle alternatives for short commutes, and (7) Targeting mode shift incentives and promotions to those most likely to change modes.

Authors:
Ulberg,C., Herman,W. G.

Keywords:
traffic surveillance and control, mode choice, multinomial logit, cluster analysis, factor analysis, transportation demand management, HOV lanes, employer policies

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Abstract:
The current project addressed two major weak points of the existing WSDOT Ramp Control System. One weak point in the system is the fact that it reacts to the problem (congestion), rather than preventing the problem. The other weak point in the system is its reliance on detector data that may be in error. Both of these problems can be minimized by developing methods to accurately predict short-term traffic data. By predicting the onset of congestion early enough, the ramp metering system can act to prevent or delay occurrence of the problem. Also, if a detector has failed or is malfunctioning, the data from the detector can be estimated from short-term predictions based on neighboring detectors. At the beginning of the current project, the researchers had hoped that the same model would provide a basis for both forecasting congestion (for predictive ramp control) and replacing erroneous data (predicting actual values). However, the best method for filling in missing detector data turned out to be multivariate time series analysis. Several pattern recognition and time series models were tested for further development. In both cases, the simpler models turned out to be the best choices, and in both cases, further model testing and development were recommended. The research on both model types continues in follow-up studies that are expected to lead to incorporation of these models in the new TSMC computer system.

Authors:
Nihan,N. L., Zhu,J.

Keywords:
bridge and construction, turner proposal, concrete bridge, fatigue, overload, replacement costs, remaining life, route assessment, maximum moments, maintenance, design loads, continuity, traffic surveillance and control, ramp controls, freeway management, traffic flow forecasts, forecast models, ramp metering

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Abstract:
Traffic performance information is an integral part of traffic control and motorist information systems. Good traffic performance information is also needed to optimize system control functions, detect congestion and incidents, and inform travelers to help them plan their trips. Yet, good traffic performance information is rarely available for these functions. One of several new technologies being investigated to improve the collection of traffic performance information is automatic vehicle identification (AVI). The primary objectives of this project were to determine the possible benefits of using AVI systems for monitoring the performance of traffic and detecting incidents. A secondary objective was to determine whether the truck fleet tagged as part of the Heavy Vehicle Electronic License Plate (HELP) project, or even the entire truck population, would provide an unbiased measure of traffic performance. The findings presented in this report show that AVI based systems can produce superior traffic performance data for use both real-time control systems and more general transportation planning and engineering analyses. Furthermore, the mathematical algorithms needed to operate the AVI system are straightforward and easily programmed. Continuing improvements in transponder, computing, and communications technologies provide the opportunity to reliably collect the information necessary to operate the planned intelligent vehicle-highway systems of the future. Given the current state of the technology and expected improvements, the impediments to using AVI technology in this manner are not technical, but fiscal and political.

Authors:
Hallenbeck,M. E., Boyle,T., Ring,J.

Keywords:
traffic surveillance and control, AVI, congestion monitoring, incident detection

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Abstract:
The purpose of this project was to determine the feasibility and evaluate the usefulness of a predictive ramp-metering algorithm that anticipates bottlenecks (a bottleneck being a reduction in the traffic capacity of the freeway) one to two minutes before their occurrence. The predictive algorithm was tested on-line in the Washington State Department of Transportation's ramp-metering central computer. The predictive algorithms accuracy in predicting bottlenecks on-line was very good, with a correct prediction rate of almost 80 percent. The measured increase in volume and decrease in occupancy during a portion of the morning peak period showed that the predictive algorithm reduced the number and/or severity of bottlenecks on the freeway test section.

Authors:
Berg,D. B., Nihan,N. L.

Keywords:
traffic surveillance and control, ramp metering, ramp controls, predictive algorithm, traffic bottlenecks

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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

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Abstract:
This report documents the Washington State Department of Transportation's examination of the potential application of adaptive signal control and integrated traffic control systems in the Seattle Metropolitan area. The research project had two sets of objectives, one for advanced, or adaptive, signal control systems and one for control system integration. The primary objectives for the advanced signal control portion of the project were to (1) investigate adaptive signal control systems, such as SCOOT, SCAT, and OPAC, (2) evaluate the UTCS 1.5 generation signal system, (3) determine applicability of, and interest in, advances signal systems on the Puget Sound Region, and (4) provide coordination with local agencies on research efforts on arterial traffic management. The primary objectives of the control system integration portion of the project were to (1) determine regional needs and interest in integrating control systems, and (2) provide coordination with local agencies on research efforts in integrated control systems. The researchers reviewed previous work in adaptive signal control and evaluate the Bellevue UTCS 1.5 signal system to determine the applicability of adaptive control in the Seattle area. Then they developed a framework for investigating integrated control system needs and met with jurisdictions throughout the Seattle Metropolitan area to discuss adaptive signal control and control system integration. Finally, they formulated conclusions and recommendations to help achieve improved coordination and integration of neighboring control systems. The UTCS 1.5 signal system has improved traffic flow on Bellevue's arterial network (volumes increased 17 percent with no significant changes in travel time), and the new system is easier to operate than the old UTCS 1.0 system. Of the adaptive control strategies investigated, UTCS 1.5 and OPAC show the most promise for implementation in the Seattle Metropolitan area. WSDOT should investigate the possibility of OPAC demonstration or test sites in the Seattle area. Local jurisdictions are interested in improved coordination and some degree of system integration. The WSDOT should keep local jurisdictions involved in and informed of the upcoming freeway and arterial control system integration project. The corridor traffic management teams that will be established should take up and help direct the area's advances in control system integration.

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

Keywords:
traffic surveillance and control, adaptive signal control, freeway and arterial integration, traffic signals, transportation management

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Abstract:
This report documents the Washington State Department of Transportation's examination of the potential application of adaptive signal control and integrated traffic control systems in the Seattle Metropolitan area. The research project had two sets of objectives, one for advanced, or adaptive, signal control systems and one for control system integration. The primary objectives for the advanced signal control portion of the project were to (1) investigate adaptive signal control systems, such as SCOOT, SCAT, and OPAC, (2) evaluate the UTCS 1.5 generation signal system, (3) determine applicability of, and interest in, advances signal systems on the Puget Sound Region, and (4) provide coordination with local agencies on research efforts on arterial traffic management. The primary objectives of the control system integration portion of the project were to (1) determine regional needs and interest in integrating control systems, and (2) provide coordination with local agencies on research efforts in integrated control systems. The researchers reviewed previous work in adaptive signal control and evaluate the Bellevue UTCS 1.5 signal system to determine the applicability of adaptive control in the Seattle area. Then they developed a framework for investigating integrated control system needs and met with jurisdictions throughout the Seattle Metropolitan area to discuss adaptive signal control and control system integration. Finally, they formulated conclusions and recommendations to help achieve improved coordination and integration of neighboring control systems. The UTCS 1.5 signal system has improved traffic flow on Bellevue's arterial network (volumes increased 17 percent with no significant changes in travel time), and the new system is easier to operate than the old UTCS 1.0 system. Of the adaptive control strategies investigated, UTCS 1.5 and OPAC show the most promise for implementation in the Seattle Metropolitan area. WSDOT should investigate the possibility of OPAC demonstration or test sites in the Seattle area. Local jurisdictions are interested in improved coordination and some degree of system integration. The WSDOT should keep local jurisdictions involved in and informed of the upcoming freeway and arterial control system integration project. The corridor traffic management teams that will be established should take up and help direct the area's advances in control system integration.

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

Keywords:
traffic surveillance and control, adaptive signal control, freeway and arterial integration, traffic signals

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Abstract:


Authors:
Rutherford,G. S., Kinchen,R. K., Jacobson,L. N.

Keywords:
traffic surveillance and control, TRB

Abstract:
The primary objectives for this study were (1) to investigate state-of-the-art techniques for providing HOV incentives on arterial routes, and (2) to generate ideas for HOV improvements applicable to urban corridors. This study was part of a research project entitled HOV Improvements on Signalized Arterials, currently under way at the University of Washington, which addresses the problem of HOV improvements on arterials in the Seattle area. The primary goal of making HOV improvements has been to increase the efficiency of transportation systems. Secondary objectives have been to reduce energy consumption, improve air quality, increase modal shift, save time travel, and reduce congestion. Reviews of existing facilities have synthesized operational results into useful generalizations. HOV facility issues include safety, enforcement, planning/design guidelines, classification schemes, and performance measures. Arterial HOV improvements have had mixed success, though lack of good before-and-after studies is significant. HOV facilities have been studied with a variety of computer models. In systems analysis, HOV lanes may be better justified as people movers when they are compared with other fixed-transit alternatives than when they are compared with automobile traffic in adjacent, non-restricted lanes.

Authors:
Nihan,N. L., Davis,J. E.

Keywords:
traffic surveillance and control, arterial HOV, HOV, high occupancy vehicle

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Abstract:
This four-volume technical report describes a study of freeway incidents and incident management strategies in the Seattle area. The study statistically analyzed the frequency and duration of freeway incidents on sections of I-5 and SR 520 in Seattle. In addition, a traffic simulation model was operationalized to assess the traffic related impacts of incidents. The findings show that Seattle-area incident management currently responds well to inclement weather and special events (e.g., major sporting games) but has problems with severe accidents. The ongoing operationalization of accident investigation sites and incident equipment storage sites can be expected to improve severe accident management, but response personnel training and the addition of more dedicated tow truck service are also needed. Finally, the study shows that, from a traffic impact perspective, the section of I-5 in downtown Seattle is in need of the most incident management attention.

Authors:
Mannering,F. L., Jones,B., Garrison,D., Sebranke,B., Janssen,L.

Keywords:
incident management, incident evaluation, incident frequency, incident duration, traffic impacts, accident analysis, traffic surveillance and control

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Abstract:
This four-volume technical report describes a study of freeway incidents and incident management strategies in the Seattle area. The study statistically analyzed the frequency and duration of freeway incidents on sections of I-5 and SR 520 in Seattle. In addition, a traffic simulation model was operationalized to assess the traffic related impacts of incidents. The findings show that Seattle-area incident management currently responds well to inclement weather and special events (e.g., major sporting games) but has problems with severe accidents. The ongoing operationalization of accident investigation sites and incident equipment storage sites can be expected to improve severe accident management, but response personnel training and the addition of more dedicated tow truck service are also needed. Finally, the study shows that, from a traffic impact perspective, the section of I-5 in downtown Seattle is in need of the most incident management attention.

Authors:
Mannering,F. L., Jones,B.

Keywords:
incident management, incident evaluation, incident frequency, incident duration, traffic impacts, accident analysis, traffic surveillance and control

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Abstract:
This four-volume technical report describes a study of freeway incidents and incident management strategies in the Seattle area. The study statistically analyzed the frequency and duration of freeway incidents on sections of I-5 and SR 520 in Seattle. In addition, a traffic simulation model was operationalized to assess the traffic related impacts of incidents. The findings show that Seattle-area incident management currently responds well to inclement weather and special events (e.g., major sporting games) but has problems with severe accidents. The ongoing operationalization of accident investigation sites and incident equipment storage sites can be expected to improve severe accident management, but response personnel training and the addition of more dedicated tow truck service are also needed. Finally, the study shows that, from a traffic impact perspective, the section of I-5 in downtown Seattle is in need of the most incident management attention.

Authors:
Mannering,F. L., Janssen,L., Sebranke,B., Jones,B.

Keywords:
incident management, incident evaluation, incident frequency, incident duration, traffic impacts, accident analysis, traffic surveillance and control

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Abstract:
This report discusses the development of recommended and alternative systems for monitoring the use of HOV lanes and compliance with HOV occupancy regulations in the Seattle Metropolitan area. The report includes a state-of-the art review of techniques for monitoring HOV lane use and the results of tests of the most promising of these techniques. In addition, the report presents a review of the existing HERO (HOV violation reporting hotline) program, including the results of a 500 person telephone survey on the public's awareness of and attitude toward HERO program and HOV facilities in general. Finally, the report describes software written to ease the storage of HERO data and improve the reporting of HERO statistics.

Authors:
Kinchen,R. K., Jacobson,L. N., Rutherford,G. S., Hallenbeck,M. E., O'Brien,A.

Keywords:
traffic surveillance and control, HOV, HOV lanes, HOV compliance, HOV violations, traffic data

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Abstract:
This report discusses the development of recommended and alternative systems for monitoring the use of HOV lanes and compliance with HOV occupancy regulations in the Seattle Metropolitan area. The report includes a state-of-the art review of techniques for monitoring HOV lane use and the results of tests of the most promising of these techniques. In addition, the report presents a review of the existing HERO (HOV violation reporting hotline) program, including the results of a 500 person telephone survey on the public's awareness of and attitude toward HERO program and HOV facilities in general. Finally, the report describes software written to ease the storage of HERO data and improve the reporting of HERO statistics.

Authors:
Kinchen,R. K., Hallenbeck,M. E., Rutherford,G. S., Jacobson,L. N., O'Brien,A.

Keywords:
traffic surveillance and control, HOV, HOV lanes, HOV compliance, HOV violations, traffic data

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Abstract:
This report documents new knowledge of Puget Sound freeway commuter behavior and information needs, relevant to the design and development of a motorist information system for the Seattle area. Methodological innovations resulted in a larger, more relevant sample; more complex and varied data; and a finer grain of analysis than previous efforts to survey motorist behavior. Findings are relevant not only to driver information systems in particular, but also to transportation management in general. Commuters were found not to be a single, homogeneous audience for motorist information, but rather to consist of four subgroups, which we labeled: (1) route changers, (2) non-changers, (3) route and time changers, and (4) pre-trip changers. Commuters were more receptive to motorist information delivered at home than to information delivered on the freeway. Most commuters were inflexible about changing transportation mode, but pre-trip changers were somewhat flexible and more likely to change mode than to change route while on the freeway. The most flexible driving decision was the departure time of route and time changers and pre-trip changers, yet the least flexible driving decision was the departure time of route changers and non-changers. Commuters were fairly flexible to on-road route changes, but less flexible than to changing pre-trip routes based on traffic information received prior to departure. Commercial radio was the preferred medium for on-road traffic information, while HAR and VMS were either not used or not generally perceived as helpful. Whatever the delivery medium, commuters questioned the credibility of motorist information. The report describes how the identification, analysis, and targeting of susceptible driver groups can improve the design of motorist information systems. Recommendations are also presented to improve commuter response to and use of HAR and VMS.

Authors:
Haselkorn,M., Barfield,W., Spyridakis,J., Conquest,L.

Keywords:
traffic surveillance and control, motorist information, advanced driver information systems, human factors, HAR, VMS, transportation management

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Abstract:
This report documents new knowledge of Puget Sound freeway commuter behavior and information needs, relevant to the design and development of a motorist information system for the Seattle area. Methodological innovations resulted in a larger, more relevant sample; more complex and varied data; and a finer grain of analysis than previous efforts to survey motorist behavior. Findings are relevant not only to driver information systems in particular, but also to transportation management in general. Commuters were found not to be a single, homogeneous audience for motorist information, but rather to consist of four subgroups, which we labeled: (1) route changers, (2) non-changers, (3) route and time changers, and (4) pre-trip changers. Commuters were more receptive to motorist information delivered at home than to information delivered on the freeway. Most commuters were inflexible about changing transportation mode, but pre-trip changers were somewhat flexible and more likely to change mode than to change route while on the freeway. The most flexible driving decision was the departure time of route and time changers and pre-trip changers, yet the least flexible driving decision was the departure time of route changers and non-changers. Commuters were fairly flexible to on-road route changes, but less flexible than to changing pre-trip routes based on traffic information received prior to departure. Commercial radio was the preferred medium for on-road traffic information, while HAR and VMS were either not used or not generally perceived as helpful. Whatever the delivery medium, commuters questioned the credibility of motorist information. The report describes how the identification, analysis, and targeting of susceptible driver groups can improve the design of motorist information systems. Recommendations are also presented to improve commuter response to and use of HAR and VMS.

Authors:
Haselkorn,M., Barfield,W., Conquest,L.

Keywords:
traffic surveillance and control, motorist information, advanced driver information systems, human factors, HAR, VMS, transportation management

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Abstract:


Authors:
O\'Brien,A.

Keywords:
traffic surveillance and control, video

Abstract:


Authors:
Kirkemo,G., Nihan,N. L., Mannering,F. L.

Keywords:
traffic surveillance and control, driver information service, cable TV, transportation systems management, behavior modeling, traffic advisories

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Abstract:


Authors:
Jacobson,L. N., Henry,K., Hehayr,O.

Keywords:
traffic surveillance and control

Abstract:


Authors:
Jacobson,L. N.

Keywords:
traffic surveillance and control, transportation planning

Abstract:
There are only limited opportunities to add significantly to the transportation infrastructure in the Puget Sound region in the next 15 to 20 years. For this reason, there is a growing interest in improving the efficiency of the existing system. One way to do this is to increase the average vehicle occupancy (AVO) on freeways and arterials. Programs to accomplish this must be capable of evaluation. Therefore, accurate and up-to-date information on AVO is required. This research project investigated various methods to measure AVO in order to determine the feasibility and costs of a continuous, ongoing data collection program. Since it was determined that there are no promising approaches using automatic methods employing new technology, the study focused on the use of human observers. The degree of accuracy was studied using three observers counting the occupancy of the same vehicle at the same time. The results showed the observers can be highly accurate (correct 97 percent of the time) and that environmental conditions such as weather, light, traffic density, and traffic speed do not have exceptionally strong effects on accuracy (within reason). Furthermore, observers can easily count up to a half hour at a time without fatigue affecting their performance. Taking the results of this and previous research into account, it was determined that it is possible to provide quarterly counts of AVO at 26 sites that are accurate to within about 1.5 percent for about $50,000 per year. This is about the cost of one data analyst, when benefits and overhead are taken into account.

Authors:
Ulberg,C., McCormack,E. D.

Keywords:
bridge and construction, piles, lateral loads, p-y curves, traffic surveillance and control, auto occupancy, traffic data, portable computer

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Abstract:


Authors:
Ulberg,C., McCormack,E. D.

Keywords:
traffic surveillance and control

Abstract:
This report is an investigation of the current methodology used to evaluate traffic sign retroreflectivity under actual highway conditions. The report consists of three parts: a literature survey, a questionnaire, and the training and analysis of human observers to rate traffic sign retroreflectivity. The literature survey and questionnaire concluded that human subjectivity judgment is almost exclusively used to evaluate traffic sign retroreflectivity. Instruments are not used for large inventories because of cost and computer-based sign management systems are in the early stages of development and not used. The questionnaire also revealed that few states have any policy for sign replacement. The main objective of the research was to assess the accuracy of using human observers to evaluate traffic sign retroreflectivity. Observers were trained to rate warning and stop sign retroreflectivity in two experiments. After the training the observers evaluated signs on two highway courses. The observer sign ratings and the sign rating calculated using a retroreflectometer were incorporated into a decision model to replace or not replace a sign based on the sign condition and environment. The individual observers made correct decisions on 74 percent of the warning signs and 75 percent of the stop signs. The literature survey and questionnaire concluded that at present there is no method of sign review other than the trained observer that is suitable for large sign inventories.. The experiments have demonstrated that a trained observer is a valuable part of a sign maintenance program. Agencies will have to continue to rely on observers' judgments for some time to come.

Authors:
Lagergren,E.

Keywords:
retroreflectivity, traffic surveillance and control

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Abstract:


Authors:
Ritchie,S. G.

Keywords:
traffic surveillance and control

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Abstract:
This report documents the survey and analysis of cities and counties in Washington that the Washington State Transportation Center (TRAC) performed to determine the potential for traffic signal timing imporvements. This report identifies the majority of signal timing optimization candidate locations in the state and presents an initial prioritized list of those sites. It is produced for the Washington State Energy Office (WSEO) to provide that agency with the preliminary information needed to develop and implement an energy usage reduction program based on management efforts to improve traffic flow.

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

Keywords:
inventory of traffic signals, traffic surveillance and control, Miscellaneous Library

Abstract:
A computerized field pavement condition survey unit and an IBM PC/XT computer base office reader and analysis system were developed for use in the pavement management program used by WSDOT. The pavement condition recording and computing device is a microprocessor controlled, data acquisition and reduction system which uses a combination of manual inputs and odometer readings to develop pavement condition reports. These reports are printed on the system printer and written to a standard compact magnetic tape cartridge along with the raw data for later inclusion in the Washington State Department of Transportation's pavement management data base. The device, including all of its attendant equipment, is fully portable so that it may be used in any motor vehicle that has an odometer pulse generator (preferably producing approximately 4,000 TTL level counts per mile) and 12 Vdc power source. The office system consists of an IBM PC/XT or AT micrcomputer with a printer and a 20 megabyte cartridge tape drive. It also has the software needed to read preview, analyze and convert the data for direct entry into WSDOT's pavement management system.

Authors:
Christensen,D. R.

Keywords:
traffic surveillance and control, pavement management, automated pavement survey equipment, pavement surface condition survey

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Abstract:
A computerized field pavement condition survey unit and an IBM PC/XT computer base office reader and analysis system were developed for use in the pavement management program used by WSDOT. The pavement condition recording and computing device is a microprocessor controlled, data acquisition and reduction system which uses a combination of manual inputs and odometer readings to develop pavement condition reports. These reports are printed on the system printer and written to a standard compact magnetic tape cartridge along with the raw data for later inclusion in the Washington State Department of Transportation's pavement management data base. The device, including all of its attendant equipment, is fully portable so that it may be used in any motor vehicle that has an odometer pulse generator (preferably producing approximately 4,000 TTL level counts per mile) and 12 Vdc power source. The office system consists of an IBM PC/XT or AT micrcomputer with a printer and a 20 megabyte cartridge tape drive. It also has the software needed to read preview, analyze and convert the data for direct entry into WSDOT's pavement management system.

Authors:
Christensen,D. R.

Keywords:
traffic surveillance and control, pavement management, automated pavement survey equipment, pavement surface condition survey

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