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• 1. [Article] The Oregon DOT Slow-Speed Weigh-In--Motion (SWIM) Project: Final Report

  Weigh-in-motion (WIM) systems have provided an effective means of data collection for pavement research and facility design, traffic monitoring, and weight enforcement for over 40 years. In weight enforcement, ...

  Citation × Citation Citation Abstract Copy Title: The Oregon DOT Slow-Speed Weigh-In--Motion (SWIM) Project: Final Report Author: Strathman, James G. Year: 1998 Weigh-in-motion (WIM) systems have provided an effective means of data collection for pavement research and facility design, traffic monitoring, and weight enforcement for over 40 years. In weight enforcement, WIM systems have been increasingly used to screen potentially overweight vehicles. Vehicles that exceed weight limits as measured on a WIM scale are then weighed on a static scale, which is subject to accuracy standards specified by the National Institute of Standards and Technology (1998). The use of WIM for screening purposes reduces queuing at weigh stations, resulting in considerable savings for both truckers and enforcement agencies. To date, however, WIM systems have not been certified for direct applications to weight enforcement. Title: The Oregon DOT Slow-Speed Weigh-In--Motion (SWIM) Project: Final Report Author: Strathman, James G. Year: 1998 Weigh-in-motion (WIM) systems have provided an effective means of data collection for pavement research and facility design, traffic monitoring, and weight enforcement for over 40 years. In weight enforcement, WIM systems have been increasingly used to screen potentially overweight vehicles. Vehicles that exceed weight limits as measured on a WIM scale are then weighed on a static scale, which is subject to accuracy standards specified by the National Institute of Standards and Technology (1998). The use of WIM for screening purposes reduces queuing at weigh stations, resulting in considerable savings for both truckers and enforcement agencies. To date, however, WIM systems have not been certified for direct applications to weight enforcement. Close

• 2. [Article] Oregon DOT Slow-Speed Weigh-in-Motion (SWIM) Project: Analysis of Initial Weight Data

  This report presents the results of a preliminary analysis of axle weights from the Oregon DOT Slow-Speed Weigh in Motion (SWIM) scale at the Wyeth weigh station.* This report includes an analysis of methodology ...

  Citation × Citation Citation Abstract Copy Title: Oregon DOT Slow-Speed Weigh-in-Motion (SWIM) Project: Analysis of Initial Weight Data Author: Swope, Tim, Strathman, James G. Year: 1997 This report presents the results of a preliminary analysis of axle weights from the Oregon DOT Slow-Speed Weigh in Motion (SWIM) scale at the Wyeth weigh station.* This report includes an analysis of methodology and variables used in the study; estimates of accuracy and precision of the WIM readings; and a regression analysis of the WIM and static scale weighings. Axles weights were collected from the traffic stream. Title: Oregon DOT Slow-Speed Weigh-in-Motion (SWIM) Project: Analysis of Initial Weight Data Author: Swope, Tim, Strathman, James G. Year: 1997 This report presents the results of a preliminary analysis of axle weights from the Oregon DOT Slow-Speed Weigh in Motion (SWIM) scale at the Wyeth weigh station.* This report includes an analysis of methodology and variables used in the study; estimates of accuracy and precision of the WIM readings; and a regression analysis of the WIM and static scale weighings. Axles weights were collected from the traffic stream. Close

• 3. [Article] Assessment and Refinement of Real-Time Travel Time Algorithms for Use in Practice

  The Federal Highway Administration (FHWA) has set a high priority on the use of existing dynamic message signs (DMS) to provide travel time estimates to the public. The Oregon Department of Transportation ...

  Citation × Citation Citation Abstract Copy Title: Assessment and Refinement of Real-Time Travel Time Algorithms for Use in Practice Author: Tufte, Kristin A., Kothuri, Sirisha Murthy Year: 2008 The Federal Highway Administration (FHWA) has set a high priority on the use of existing dynamic message signs (DMS) to provide travel time estimates to the public. The Oregon Department of Transportation (ODOT) currently has three DMS in the Portland metropolitan area configured to display travel time information. In the near future, ODOT would like to make travel time estimates available on additional DMS, over the Internet on tripcheck.com and via 511. Travel time estimates are valuable to the traveling public; however, the estimates must be accurate to be useful. The FHWA indicates that 90% accuracy is ideal and suggests a minimum accuracy of 80%. Thus, in order to display travel time estimates, it is essential to understand the accuracy of the estimates. The purpose of this study is to extend prior travel time research conducted at Portland State University with additional data collection and analysis to provide statistical confidence in travel time estimates and to determine the best travel time estimation approach for ODOT. Ground truth data in the form of probe vehicle runs will be collected and travel time estimates will be evaluated using that data. Several travel time estimation algorithms will be evaluated and modifications to existing algorithms will be proposed. In addition, this project will provide analysis to help understand the reliability and performance of the algorithms under various conditions (free-flow, congestion, incidents). A methodology will be developed for determining if travel time estimates fall within an acceptable accuracy limits. At the conclusion of the project, it is desired that a methodology can be recommended that will provide accurate measures of travel time for use with DMS, the Internet and 511 applications. Title: Assessment and Refinement of Real-Time Travel Time Algorithms for Use in Practice Author: Tufte, Kristin A., Kothuri, Sirisha Murthy Year: 2008 The Federal Highway Administration (FHWA) has set a high priority on the use of existing dynamic message signs (DMS) to provide travel time estimates to the public. The Oregon Department of Transportation (ODOT) currently has three DMS in the Portland metropolitan area configured to display travel time information. In the near future, ODOT would like to make travel time estimates available on additional DMS, over the Internet on tripcheck.com and via 511. Travel time estimates are valuable to the traveling public; however, the estimates must be accurate to be useful. The FHWA indicates that 90% accuracy is ideal and suggests a minimum accuracy of 80%. Thus, in order to display travel time estimates, it is essential to understand the accuracy of the estimates. The purpose of this study is to extend prior travel time research conducted at Portland State University with additional data collection and analysis to provide statistical confidence in travel time estimates and to determine the best travel time estimation approach for ODOT. Ground truth data in the form of probe vehicle runs will be collected and travel time estimates will be evaluated using that data. Several travel time estimation algorithms will be evaluated and modifications to existing algorithms will be proposed. In addition, this project will provide analysis to help understand the reliability and performance of the algorithms under various conditions (free-flow, congestion, incidents). A methodology will be developed for determining if travel time estimates fall within an acceptable accuracy limits. At the conclusion of the project, it is desired that a methodology can be recommended that will provide accurate measures of travel time for use with DMS, the Internet and 511 applications. Close

• 4. [Article] Tri-Met's Experience With Automatic Passenger Counter and Automatic Vehicle Location Systems

  The Tri-County Metropolitan Transportation District of Oregon (Tri-Met) is one of about 30 metropolitan transit agencies that have deployed both automatic vehicle location (AVL) and automatic passenger ...

  Citation × Citation Citation Abstract Copy Title: Tri-Met's Experience With Automatic Passenger Counter and Automatic Vehicle Location Systems Author: Strathman, James G. Year: 2002 The Tri-County Metropolitan Transportation District of Oregon (Tri-Met) is one of about 30 metropolitan transit agencies that have deployed both automatic vehicle location (AVL) and automatic passenger counter (APC) systems (Casey, 1999). These technologies are important components of the agency’s new automated bus dispatching system (BDS). The AVL and APC systems at Tri-Met recover comprehensive operations and passenger activity data at the bus stop level that is archived for later analysis. The agency has gained a reputation as an industry leader in the areas of data archiving and the application of archived data to performance monitoring and analysis. Prior to the implementation of AVL and APC technology, Tri-Met, like others in the transit industry, relied on costly manual data recovery. During lean budget years in the early 1980s, the agency began using stand-alone APCs instead of ride checkers, and recovered very little operating data beyond what was required for Federal Transit Administration reporting. With its AVL and APC systems, Tri-Met is now automatically collecting and archiving over 500,000 stop and event data records per day. Offline analysis of this data supports a wide array of agency activities. The transformation from scarce to abundant data has contributed to a variety of functional changes that have both enhanced service quality and improved efficiency. This report examines factors related to the development of Tri-Met’s BDS that have contributed to its success in data archiving and analysis. The organization of the report includes a description of the BDS, a review of the types of analyses that have been supported by archived data, a discussion of factors that influenced decisions made on the design of the system, reflections on unrealized expectations and missed opportunities, and concluding observations. Title: Tri-Met's Experience With Automatic Passenger Counter and Automatic Vehicle Location Systems Author: Strathman, James G. Year: 2002 The Tri-County Metropolitan Transportation District of Oregon (Tri-Met) is one of about 30 metropolitan transit agencies that have deployed both automatic vehicle location (AVL) and automatic passenger counter (APC) systems (Casey, 1999). These technologies are important components of the agency’s new automated bus dispatching system (BDS). The AVL and APC systems at Tri-Met recover comprehensive operations and passenger activity data at the bus stop level that is archived for later analysis. The agency has gained a reputation as an industry leader in the areas of data archiving and the application of archived data to performance monitoring and analysis. Prior to the implementation of AVL and APC technology, Tri-Met, like others in the transit industry, relied on costly manual data recovery. During lean budget years in the early 1980s, the agency began using stand-alone APCs instead of ride checkers, and recovered very little operating data beyond what was required for Federal Transit Administration reporting. With its AVL and APC systems, Tri-Met is now automatically collecting and archiving over 500,000 stop and event data records per day. Offline analysis of this data supports a wide array of agency activities. The transformation from scarce to abundant data has contributed to a variety of functional changes that have both enhanced service quality and improved efficiency. This report examines factors related to the development of Tri-Met’s BDS that have contributed to its success in data archiving and analysis. The organization of the report includes a description of the BDS, a review of the types of analyses that have been supported by archived data, a discussion of factors that influenced decisions made on the design of the system, reflections on unrealized expectations and missed opportunities, and concluding observations. Close

• 5. [Article] Modeling and Analyzing the Impact of Advanced Technologies on Transit Performance Measures in Arterial Corridors

  Transportation and transit agencies have implemented advanced technologies like transit signal priority (TSP) and Sydney Coordinated Adaptive Traffic System (SCATS) to reduce travel times and improve reliability. ...

  Citation × Citation Citation Abstract Copy Title: Modeling and Analyzing the Impact of Advanced Technologies on Transit Performance Measures in Arterial Corridors Author: Figliozzi, Miguel A., Feng, Wei Year: 2014 Transportation and transit agencies have implemented advanced technologies like transit signal priority (TSP) and Sydney Coordinated Adaptive Traffic System (SCATS) to reduce travel times and improve reliability. However, due to the lack of detailed empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level. With the aim of assessing the performance of an existing TSP/SCATS system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a timely and effective TSP system requires a high degree of sophistication, monitoring and maintenance. Empirical data suggest that most TSP phase adjustments were granted in time (i.e., within a cycle) to buses that requested priority, but that only a small proportion resulted in reduced delay. In this study, many green extension phases were granted late, making them less effective than early green signal phases. Despite this, the TSP system did not increase delays for passengers and vehicles when side-street traffic is also considered. Title: Modeling and Analyzing the Impact of Advanced Technologies on Transit Performance Measures in Arterial Corridors Author: Figliozzi, Miguel A., Feng, Wei Year: 2014 Transportation and transit agencies have implemented advanced technologies like transit signal priority (TSP) and Sydney Coordinated Adaptive Traffic System (SCATS) to reduce travel times and improve reliability. However, due to the lack of detailed empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level. With the aim of assessing the performance of an existing TSP/SCATS system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a timely and effective TSP system requires a high degree of sophistication, monitoring and maintenance. Empirical data suggest that most TSP phase adjustments were granted in time (i.e., within a cycle) to buses that requested priority, but that only a small proportion resulted in reduced delay. In this study, many green extension phases were granted late, making them less effective than early green signal phases. Despite this, the TSP system did not increase delays for passengers and vehicles when side-street traffic is also considered. Close