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• 1. [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

• 2. [Article] An Evaluation of Automatic Passenger Counters: Validation, Sampling, and Statistical Inference

  While automatic passenger counters (APC's) offer the potential for cait effective data recovery and management, they also introduce new complications in the data recovery process. This report addresses ...

  Citation × Citation Citation Abstract Copy Title: An Evaluation of Automatic Passenger Counters: Validation, Sampling, and Statistical Inference Author: Strathman, James G. Year: 1989 While automatic passenger counters (APC's) offer the potential for cait effective data recovery and management, they also introduce new complications in the data recovery process. This report addresses three issues associated with the implementation of APC's, based on an evaluation of the recent experiences of the Tri-County Metropolitan Transportation District of Oregon (Tri-Met). First is the issue of validation, which is concerned with both the recovery and accuracy of APC passenger data. The second issue concerns the development of a sampling methodology for APC's compatible with UMTA's Section 15 reporting requirements. Third is the issue of inferring system-level ridership from sample data in the presence of selective APC failures. We find that the APC's are providing systematically accurate passenger counts. Analysis of the data recovered from September to November 1988 also shows that sampling was representative, based on the set of "trains" from which ridership data were successfully recovered. The initial selection/assignment of trains, however, was not representative. Given that APC's record operating data for all bus trips comprising a train assignment, a cluster sampling method is formulated that ensures an overall random selection of bus trips via a random first stage selection of trains. Selective data recovery failures can hamper the process of inferring system-level ridership from the sample estimates. For example, when failure rates vary by bus type or time of day, inferences drawn from the sample of recovered data may over or under-represent total system ridership. In such circumstances, post hoc stratification of the sample data may be required. We outline several alternative corrections based on a-priori knowledge of the mix of bus types and schedule characteristics in the system. Title: An Evaluation of Automatic Passenger Counters: Validation, Sampling, and Statistical Inference Author: Strathman, James G. Year: 1989 While automatic passenger counters (APC's) offer the potential for cait effective data recovery and management, they also introduce new complications in the data recovery process. This report addresses three issues associated with the implementation of APC's, based on an evaluation of the recent experiences of the Tri-County Metropolitan Transportation District of Oregon (Tri-Met). First is the issue of validation, which is concerned with both the recovery and accuracy of APC passenger data. The second issue concerns the development of a sampling methodology for APC's compatible with UMTA's Section 15 reporting requirements. Third is the issue of inferring system-level ridership from sample data in the presence of selective APC failures. We find that the APC's are providing systematically accurate passenger counts. Analysis of the data recovered from September to November 1988 also shows that sampling was representative, based on the set of "trains" from which ridership data were successfully recovered. The initial selection/assignment of trains, however, was not representative. Given that APC's record operating data for all bus trips comprising a train assignment, a cluster sampling method is formulated that ensures an overall random selection of bus trips via a random first stage selection of trains. Selective data recovery failures can hamper the process of inferring system-level ridership from the sample estimates. For example, when failure rates vary by bus type or time of day, inferences drawn from the sample of recovered data may over or under-represent total system ridership. In such circumstances, post hoc stratification of the sample data may be required. We outline several alternative corrections based on a-priori knowledge of the mix of bus types and schedule characteristics in the system. Close

• 3. [Article] Evaluation of Transit Operations: Data Applications of Tri-Met’s Automated Bus Dispatching System

  Over the past decade, the adoption of Advanced Public Transportation System (APTS) technology has been motivated by transit providers’ desire to improve service reliability as well as to identify potential ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of Transit Operations: Data Applications of Tri-Met’s Automated Bus Dispatching System Author: Strathman, James G., Kimpel, Thomas J., Dueker, Kenneth, Gerhart, Rick, Callas, Steve Year: 2001 Over the past decade, the adoption of Advanced Public Transportation System (APTS) technology has been motivated by transit providers’ desire to improve service reliability as well as to identify potential savings from improvements in scheduling and service planning. Casey (2000) reports that Automatic Vehicle Location (AVL) systems, a cornerstone of APTS, have been deployed by 61 transit agencies as of 1998. Title: Evaluation of Transit Operations: Data Applications of Tri-Met’s Automated Bus Dispatching System Author: Strathman, James G., Kimpel, Thomas J., Dueker, Kenneth, Gerhart, Rick, Callas, Steve Year: 2001 Over the past decade, the adoption of Advanced Public Transportation System (APTS) technology has been motivated by transit providers’ desire to improve service reliability as well as to identify potential savings from improvements in scheduling and service planning. Casey (2000) reports that Automatic Vehicle Location (AVL) systems, a cornerstone of APTS, have been deployed by 61 transit agencies as of 1998. Close

• 4. [Article] Analysis of Transit Fare Evasion in the Rose Quarter

  Tri-Met collected fare evasion data for buses and MAX trains passing outbound through the Rose Quarter Monday, June 11 through Saturday, July 7. Beginning September 2001, Tri-Met’s “Fareless Square’s” ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Transit Fare Evasion in the Rose Quarter Author: Isreal, Shimon, Strathman, James G. Year: 2002 Tri-Met collected fare evasion data for buses and MAX trains passing outbound through the Rose Quarter Monday, June 11 through Saturday, July 7. Beginning September 2001, Tri-Met’s “Fareless Square’s” free zone was extended towards the Lloyd District, with an eastern boundary of NE 14th. Prior to this, all trips between the Central Business District and Lloyd Center required a full Zone 1 fare. Title: Analysis of Transit Fare Evasion in the Rose Quarter Author: Isreal, Shimon, Strathman, James G. Year: 2002 Tri-Met collected fare evasion data for buses and MAX trains passing outbound through the Rose Quarter Monday, June 11 through Saturday, July 7. Beginning September 2001, Tri-Met’s “Fareless Square’s” free zone was extended towards the Lloyd District, with an eastern boundary of NE 14th. Prior to this, all trips between the Central Business District and Lloyd Center required a full Zone 1 fare. Close

• 5. [Article] Issues in the Design of a Stop-Level Transit Patronage Model

  Tri-Met, the transit agency serving the Portland, Oregon metropolitan area is implementing a new bus dispatching system (BDS) that includes automated vehicle location (AVL) technology. An important objective ...

  Citation × Citation Citation Abstract Copy Title: Issues in the Design of a Stop-Level Transit Patronage Model Author: Strathman, James G., Dueker, Kenneth, Peng, Zhongren Year: 1997 Tri-Met, the transit agency serving the Portland, Oregon metropolitan area is implementing a new bus dispatching system (BDS) that includes automated vehicle location (AVL) technology. An important objective in the agency's decision to invest in a new dispatching system was to maintain or improve service reliability in an urban environment characterized by rapid growth and worsening traffic congestion. Title: Issues in the Design of a Stop-Level Transit Patronage Model Author: Strathman, James G., Dueker, Kenneth, Peng, Zhongren Year: 1997 Tri-Met, the transit agency serving the Portland, Oregon metropolitan area is implementing a new bus dispatching system (BDS) that includes automated vehicle location (AVL) technology. An important objective in the agency's decision to invest in a new dispatching system was to maintain or improve service reliability in an urban environment characterized by rapid growth and worsening traffic congestion. Close

• 6. [Article] Development of a Statistical Algorithm for the Real-Time Prediction of Transit Vehicle Arrival Times Under Adverse Conditions

  Prior TransNow funded research by Portland State University (PSU) and the University of Washington (UW) in cooperation with Tri-Met, the transit provider for the Portland metropolitan area, has utilized ...

  Citation × Citation Citation Abstract Copy Title: Development of a Statistical Algorithm for the Real-Time Prediction of Transit Vehicle Arrival Times Under Adverse Conditions Author: Dueker, Kenneth, Kimpel, Thomas J., Strathman, James G. Year: 2001 Prior TransNow funded research by Portland State University (PSU) and the University of Washington (UW) in cooperation with Tri-Met, the transit provider for the Portland metropolitan area, has utilized a rich set of archived data from the Automatic Vehicle Location (AVL)-based Bus Dispatch System (BDS). Tri-Met is one of the few transit agencies that archive AVL data for analysis and research. Title: Development of a Statistical Algorithm for the Real-Time Prediction of Transit Vehicle Arrival Times Under Adverse Conditions Author: Dueker, Kenneth, Kimpel, Thomas J., Strathman, James G. Year: 2001 Prior TransNow funded research by Portland State University (PSU) and the University of Washington (UW) in cooperation with Tri-Met, the transit provider for the Portland metropolitan area, has utilized a rich set of archived data from the Automatic Vehicle Location (AVL)-based Bus Dispatch System (BDS). Tri-Met is one of the few transit agencies that archive AVL data for analysis and research. Close

• 7. [Article] Automated Bus Dispatching, Operations Control, and Service Reliability: The Initial Tri-Met Experience

  This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. ...

  Citation × Citation Citation Abstract Copy Title: Automated Bus Dispatching, Operations Control, and Service Reliability: The Initial Tri-Met Experience Author: Strathman, James G., Dueker, Kenneth, Kimpel, Thomas J., Gerhart, Rick, Turner, Ken, Taylor, Pete, Callas, Steve, Griffin, David Year: 1999 This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. Changes in on-time performance, headway variation, run time variation, and run times were determined with respect to pre-deployment levels. Changes in headway variation and run times were also used to estimate the initial benefits of the new system with respect to operating costs, passenger waiting, and passenger travel time. Title: Automated Bus Dispatching, Operations Control, and Service Reliability: The Initial Tri-Met Experience Author: Strathman, James G., Dueker, Kenneth, Kimpel, Thomas J., Gerhart, Rick, Turner, Ken, Taylor, Pete, Callas, Steve, Griffin, David Year: 1999 This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. Changes in on-time performance, headway variation, run time variation, and run times were determined with respect to pre-deployment levels. Changes in headway variation and run times were also used to estimate the initial benefits of the new system with respect to operating costs, passenger waiting, and passenger travel time. Close

• 8. [Article] Service Reliability Impacts of Computer-Aided Dispatching and Automatic Vehicle Location Technology: A Tri-Met Case Study

  This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. ...

  Citation × Citation Citation Abstract Copy Title: Service Reliability Impacts of Computer-Aided Dispatching and Automatic Vehicle Location Technology: A Tri-Met Case Study Author: Strathman, James G., Dueker, Kenneth, Kimpel, Thomas J., Gerhart, Rick, Turner, Ken, Turner, Pete, Callas, Steve, Griffin, David Year: 1999 This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. Changes in on-time performance, headway variation, run time variation, and run times were determined with respect to pre-deployment levels. Changes in headway variation and run times were also used to estimate the initial benefits of the new system with respect to operating costs, passenger waiting, and passenger travel time. Title: Service Reliability Impacts of Computer-Aided Dispatching and Automatic Vehicle Location Technology: A Tri-Met Case Study Author: Strathman, James G., Dueker, Kenneth, Kimpel, Thomas J., Gerhart, Rick, Turner, Ken, Turner, Pete, Callas, Steve, Griffin, David Year: 1999 This paper presents findings on initial changes in service reliability following Tri-Met’s deployment of a new bus dispatching system using automatic vehicle location and automatic passenger counter technology. Changes in on-time performance, headway variation, run time variation, and run times were determined with respect to pre-deployment levels. Changes in headway variation and run times were also used to estimate the initial benefits of the new system with respect to operating costs, passenger waiting, and passenger travel time. Close

• 9. [Article] Headway Deviation Effects on Bus Passenger Loads: Analysis of Tri-Met’s Archived AVL-APC Data

  In this paper we empirically analyze the relationship between transit service headway deviations and passenger loads, using archived data from Tri-Met’s automatic vehicle location and automatic passenger ...

  Citation × Citation Citation Abstract Copy Title: Headway Deviation Effects on Bus Passenger Loads: Analysis of Tri-Met’s Archived AVL-APC Data Author: Strathman, James G., Kimpel, Thomas J., Callas, Steve Year: 2003 In this paper we empirically analyze the relationship between transit service headway deviations and passenger loads, using archived data from Tri-Met’s automatic vehicle location and automatic passenger counter systems. The analysis employs two-stage least squares estimation to account for the simultaneous relationship between headway deviations and loads. Controlling for the effects of passenger activity on delay, the results indicate that the observed incidence of excess passenger loads is systematically attributable to deviations from scheduled headways. In turn, analysis of the causes of headway deviations served to identify possible operations control actions that would improve service regularity and, consequently, reduce incidences of overloading and forestall the need for additional service. Title: Headway Deviation Effects on Bus Passenger Loads: Analysis of Tri-Met’s Archived AVL-APC Data Author: Strathman, James G., Kimpel, Thomas J., Callas, Steve Year: 2003 In this paper we empirically analyze the relationship between transit service headway deviations and passenger loads, using archived data from Tri-Met’s automatic vehicle location and automatic passenger counter systems. The analysis employs two-stage least squares estimation to account for the simultaneous relationship between headway deviations and loads. Controlling for the effects of passenger activity on delay, the results indicate that the observed incidence of excess passenger loads is systematically attributable to deviations from scheduled headways. In turn, analysis of the causes of headway deviations served to identify possible operations control actions that would improve service regularity and, consequently, reduce incidences of overloading and forestall the need for additional service. Close

• 10. [Article] Analysis of Transit Signal Priority Using Archived TriMet Bus Dispatch System Data

  This paper presents findings on changes in bus running times, on-time performance, and excess passenger wait times following implementation of transit signal priority in select bus corridors in the Portland ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Transit Signal Priority Using Archived TriMet Bus Dispatch System Data Author: Kimpel, Thomas J., Strathman, James G., Bertini, Robert L., Callas, Steve Year: 2005 This paper presents findings on changes in bus running times, on-time performance, and excess passenger wait times following implementation of transit signal priority in select bus corridors in the Portland metropolitan region. Analysis of the effectiveness of transit signal priority is often undertaken using simulation techniques or empirical studies that are either limited in scope and/or data availability. The present research uses an abundance of trip-level data collected from TriMet’s Bus Dispatch System. The study focuses on the most common performance measures of interest to both transit operators and passengers. Our study shows that the expected benefits of TSP are not consistent across routes and time periods, nor are they consistent across the various performance measures. We believe that benefits of transit signal priority will accrue only as the result of extensive evaluation and adjustment initial deployment. In most cases, an ongoing performance monitoring and adjustment program should be implemented in order to maximize the benefits of transit signal priority. Title: Analysis of Transit Signal Priority Using Archived TriMet Bus Dispatch System Data Author: Kimpel, Thomas J., Strathman, James G., Bertini, Robert L., Callas, Steve Year: 2005 This paper presents findings on changes in bus running times, on-time performance, and excess passenger wait times following implementation of transit signal priority in select bus corridors in the Portland metropolitan region. Analysis of the effectiveness of transit signal priority is often undertaken using simulation techniques or empirical studies that are either limited in scope and/or data availability. The present research uses an abundance of trip-level data collected from TriMet’s Bus Dispatch System. The study focuses on the most common performance measures of interest to both transit operators and passengers. Our study shows that the expected benefits of TSP are not consistent across routes and time periods, nor are they consistent across the various performance measures. We believe that benefits of transit signal priority will accrue only as the result of extensive evaluation and adjustment initial deployment. In most cases, an ongoing performance monitoring and adjustment program should be implemented in order to maximize the benefits of transit signal priority. Close