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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