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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] Analysis of Bus Collision Incidents Using Transit ITS and other Archived Operations Data

  This report analyzes factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland Oregon metropolitan region. The analysis focuses on 4,631 collision and non-collision ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Bus Collision Incidents Using Transit ITS and other Archived Operations Data Author: Strathman, James G., Wachana, Paul Herman, Callas, Steve Year: 2010 This report analyzes factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland Oregon metropolitan region. The analysis focuses on 4,631 collision and non-collision incidents that occurred between 2006 and 2009. Empirical analysis of these incidents draws on a wide array of operator-level data recovered by transit ITS technologies in combination with information from TriMet’s human resources, scheduling, and customer relations databases. Incident frequencies are estimated in relation to operators’ demographic characteristics, employment status, assigned work characteristics, service delivery and performance indicators, temporal factors, and customer information. Apart from identifying factors that are empirically related to the frequency of safety incidents, the findings offer insights into operations policies and practices that hold promise for improving safety. Title: Analysis of Bus Collision Incidents Using Transit ITS and other Archived Operations Data Author: Strathman, James G., Wachana, Paul Herman, Callas, Steve Year: 2010 This report analyzes factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland Oregon metropolitan region. The analysis focuses on 4,631 collision and non-collision incidents that occurred between 2006 and 2009. Empirical analysis of these incidents draws on a wide array of operator-level data recovered by transit ITS technologies in combination with information from TriMet’s human resources, scheduling, and customer relations databases. Incident frequencies are estimated in relation to operators’ demographic characteristics, employment status, assigned work characteristics, service delivery and performance indicators, temporal factors, and customer information. Apart from identifying factors that are empirically related to the frequency of safety incidents, the findings offer insights into operations policies and practices that hold promise for improving safety. Close

• 4. [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

• 5. [Article] Overlooked Destinations: Suburban Nodes, Centers, and Trips to Strips

  This study looks at travel to typical suburban commercial strips by residents living within one-third of a mile of the strip by focusing on six sites – four in the Portland, OR., metro area and two in ...

  Citation × Citation Citation Abstract Copy Title: Overlooked Destinations: Suburban Nodes, Centers, and Trips to Strips Author: Larco, Nico, Parker, Robert Year: 2013 This study looks at travel to typical suburban commercial strips by residents living within one-third of a mile of the strip by focusing on six sites – four in the Portland, OR., metro area and two in the Atlanta, GA., metro area. The study mapped pedsheds around the commercial strips in these sites and found significant increases in network extents when formal and informal pedestrian paths were added to street centerline data. Informal networks such as goat paths through vacant land and cuts in fences were widespread and suggest a pent-up demand for route directness. Travel surveys of residents found significant amounts of walking and biking in these areas – just over one-third of all trips to the commercial strip – with travel distance and walking along or across arterials affecting mode choice. This suggests network extent and connectivity to be a critical factor in increasing walking and biking in these suburban areas. Resident motivations behind mode choice included convenience (which mode is easiest); cost (active travel is less expensive than auto travel); and culture (a pattern of driving or active travel, regardless of ease or cost). There was little variation across sites, suggesting that this level of active travel and the motivations behind it are fairly consistent, with a few variations, across income and geography. Title: Overlooked Destinations: Suburban Nodes, Centers, and Trips to Strips Author: Larco, Nico, Parker, Robert Year: 2013 This study looks at travel to typical suburban commercial strips by residents living within one-third of a mile of the strip by focusing on six sites – four in the Portland, OR., metro area and two in the Atlanta, GA., metro area. The study mapped pedsheds around the commercial strips in these sites and found significant increases in network extents when formal and informal pedestrian paths were added to street centerline data. Informal networks such as goat paths through vacant land and cuts in fences were widespread and suggest a pent-up demand for route directness. Travel surveys of residents found significant amounts of walking and biking in these areas – just over one-third of all trips to the commercial strip – with travel distance and walking along or across arterials affecting mode choice. This suggests network extent and connectivity to be a critical factor in increasing walking and biking in these suburban areas. Resident motivations behind mode choice included convenience (which mode is easiest); cost (active travel is less expensive than auto travel); and culture (a pattern of driving or active travel, regardless of ease or cost). There was little variation across sites, suggesting that this level of active travel and the motivations behind it are fairly consistent, with a few variations, across income and geography. Close

• 6. [Article] Maintaining Safe, Efficient and Sustainable Intermodal Transport Through the Port of Portland

  About $15 billion of freight passes annually through the Lower Columbia River (LCR) navigation channel to reach Portland and Vancouver, where most of it connects with land transport. This commerce plays ...

  Citation × Citation Citation Abstract Copy Title: Maintaining Safe, Efficient and Sustainable Intermodal Transport Through the Port of Portland Author: Jay, David A., Pan, Jiayi Year: 2011 About $15 billion of freight passes annually through the Lower Columbia River (LCR) navigation channel to reach Portland and Vancouver, where most of it connects with land transport. This commerce plays a vital role in sustaining the regional economy and connecting Oregon to the global economy. The timely connection of truck and rail transport with vessels is vital, especially for export traffic. This link is susceptible to disruption if water depths in the navigation channel are shallower than expected, leading to delays and/or draft limitations. Moreover, ship drafts have increased in recent decades, 25% of the vessels calling in the river sail with a draft close to the channel depth at low water, and these carry roughly 70% of the cargo. A large vessel may have as little as 0.6 m bed clearance when it passes through a low-tide point in the river, which each vessel in transit must do. Thus, prediction and real-time communication of water level to vessels is vital to safety as well as efficiency. This has been implemented through the LOADMAX system, consisting of telemetered water-level gauges and a forecast model. Moreover, the dilemma has been made more critical by changes in the river – low water levels in the river channel between Wauna and Vancouver have decreased 0.3-1.2 m since 1940. The rate of decrease depends on location and riverflow, but appears to have accelerated in the last decade. The reasons for this decrease are not understood. For perspective, an ongoing 0.9 m channel deepening will cost about $150 million when completed, so unintended decreases in water depths are expensive as well as potentially dangerous. Lower water levels in the river also increase carbon emissions, because smaller loads mean more land and vessel transport trips. Further, navigation and salmon habitat restoration are closely connected. Dredging is used to maintain the channel, and habitat restoration is an integral part of the channel deepening. New dredging strategies are needed to maintain the newly deepened channel, but dredging that removes material permanently from the river may, further lower water levels, limiting possibilities for habitat restoration and reducing bed clearance for large ships. These problems will be exacerbated by future decreases in summer river flows due to climate change. Title: Maintaining Safe, Efficient and Sustainable Intermodal Transport Through the Port of Portland Author: Jay, David A., Pan, Jiayi Year: 2011 About $15 billion of freight passes annually through the Lower Columbia River (LCR) navigation channel to reach Portland and Vancouver, where most of it connects with land transport. This commerce plays a vital role in sustaining the regional economy and connecting Oregon to the global economy. The timely connection of truck and rail transport with vessels is vital, especially for export traffic. This link is susceptible to disruption if water depths in the navigation channel are shallower than expected, leading to delays and/or draft limitations. Moreover, ship drafts have increased in recent decades, 25% of the vessels calling in the river sail with a draft close to the channel depth at low water, and these carry roughly 70% of the cargo. A large vessel may have as little as 0.6 m bed clearance when it passes through a low-tide point in the river, which each vessel in transit must do. Thus, prediction and real-time communication of water level to vessels is vital to safety as well as efficiency. This has been implemented through the LOADMAX system, consisting of telemetered water-level gauges and a forecast model. Moreover, the dilemma has been made more critical by changes in the river – low water levels in the river channel between Wauna and Vancouver have decreased 0.3-1.2 m since 1940. The rate of decrease depends on location and riverflow, but appears to have accelerated in the last decade. The reasons for this decrease are not understood. For perspective, an ongoing 0.9 m channel deepening will cost about $150 million when completed, so unintended decreases in water depths are expensive as well as potentially dangerous. Lower water levels in the river also increase carbon emissions, because smaller loads mean more land and vessel transport trips. Further, navigation and salmon habitat restoration are closely connected. Dredging is used to maintain the channel, and habitat restoration is an integral part of the channel deepening. New dredging strategies are needed to maintain the newly deepened channel, but dredging that removes material permanently from the river may, further lower water levels, limiting possibilities for habitat restoration and reducing bed clearance for large ships. These problems will be exacerbated by future decreases in summer river flows due to climate change. Close