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• 1. [Article] Analysis of Design Attributes and Crashes on the Oregon Highway System

  Since the passage of the Highway Safety Act of 1966, state departments of transportation have engaged in systematic safety improvement planning and programming. According to Davis (2000), the general approach ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Design Attributes and Crashes on the Oregon Highway System Author: Strathman, James G., Dueker, Kenneth, Zhang, Jihong, Williams, Timothy Year: 2001 Since the passage of the Highway Safety Act of 1966, state departments of transportation have engaged in systematic safety improvement planning and programming. According to Davis (2000), the general approach to safety improvement planning employed by most states follows six principal steps: 1. Identification of hazardous roadway locations using crash records; 2. Detailed engineering study of selected hazardous locations to identify roadway design problems; 3. Identification of potential countermeasures; 4. Assessment of the costs and benefits of potential countermeasures; 5. Implementation of countermeasures with the highest net benefits; 6. Assessment of countermeasure effectiveness following implementation. All planning processes are subject to uncertainty. In safety improvement planning, the determination of benefits from implementation of countermeasures depends greatly on projected crash reductions. Such projections are acknowledged to be the most uncertain element of the safety planning process (Pfefer et al., 1999). More than 25 years ago Laughland et al. (1975) identified the need for development of a national comprehensive set of crash reduction factors (CRFs) that states could employ in evaluating safety countermeasures. However, this need has not been addressed, and is not likely to be pursued (FHWA, 1991). As a result, states have been responsible for developing their own CRFs. Title: Analysis of Design Attributes and Crashes on the Oregon Highway System Author: Strathman, James G., Dueker, Kenneth, Zhang, Jihong, Williams, Timothy Year: 2001 Since the passage of the Highway Safety Act of 1966, state departments of transportation have engaged in systematic safety improvement planning and programming. According to Davis (2000), the general approach to safety improvement planning employed by most states follows six principal steps: 1. Identification of hazardous roadway locations using crash records; 2. Detailed engineering study of selected hazardous locations to identify roadway design problems; 3. Identification of potential countermeasures; 4. Assessment of the costs and benefits of potential countermeasures; 5. Implementation of countermeasures with the highest net benefits; 6. Assessment of countermeasure effectiveness following implementation. All planning processes are subject to uncertainty. In safety improvement planning, the determination of benefits from implementation of countermeasures depends greatly on projected crash reductions. Such projections are acknowledged to be the most uncertain element of the safety planning process (Pfefer et al., 1999). More than 25 years ago Laughland et al. (1975) identified the need for development of a national comprehensive set of crash reduction factors (CRFs) that states could employ in evaluating safety countermeasures. However, this need has not been addressed, and is not likely to be pursued (FHWA, 1991). As a result, states have been responsible for developing their own CRFs. Close

• 2. [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

• 3. [Article] Automated Bus Dispatching, Operations, Control, and Service Reliability: Baseline Analysis

  The authors of this report are engaged in a long term project to assess the impacts of Tri-Met's BDS on service reliability and transit use. The framework designed for this assessment focuses on documenting ...

  Citation × Citation Citation Abstract Copy Title: Automated Bus Dispatching, Operations, Control, and Service Reliability: Baseline Analysis Author: Strathman, James G., Dueker, Kenneth, Kimpel, Thomas J., Gerhart, Rick, Turner, Ken, Taylor, Pete, Callas, Steve, Griffin, David, Hopper, Janet Year: 1998 The authors of this report are engaged in a long term project to assess the impacts of Tri-Met's BDS on service reliability and transit use. The framework designed for this assessment focuses on documenting service reliability and passenger activity at three major junctures: • The pre-operational (baseline) period; • The initial (passive) period following implementation of the new system, when both drivers and dispatchers have access to schedule adherence information in real time, but before the development and use of operations control practices that exploit the information generated by the system; • Full implementation, when operations control practices are defined and actively employed by dispatchers and field supervisors, and when performance data is used in wriling schedules. The baseline analysis documents service reliability on eight routes that were selected to be representative of the typology of routes in Tri-Met's system. Data on weekday run times, headways, and on-time performance were recovered over a two week period in November 1996. Findings from analysis of these data are presented in this report. Title: Automated Bus Dispatching, Operations, Control, and Service Reliability: Baseline Analysis Author: Strathman, James G., Dueker, Kenneth, Kimpel, Thomas J., Gerhart, Rick, Turner, Ken, Taylor, Pete, Callas, Steve, Griffin, David, Hopper, Janet Year: 1998 The authors of this report are engaged in a long term project to assess the impacts of Tri-Met's BDS on service reliability and transit use. The framework designed for this assessment focuses on documenting service reliability and passenger activity at three major junctures: • The pre-operational (baseline) period; • The initial (passive) period following implementation of the new system, when both drivers and dispatchers have access to schedule adherence information in real time, but before the development and use of operations control practices that exploit the information generated by the system; • Full implementation, when operations control practices are defined and actively employed by dispatchers and field supervisors, and when performance data is used in wriling schedules. The baseline analysis documents service reliability on eight routes that were selected to be representative of the typology of routes in Tri-Met's system. Data on weekday run times, headways, and on-time performance were recovered over a two week period in November 1996. Findings from analysis of these data are presented in this report. Close

• 4. [Article] Bus Transit Operations Control: Review and an Experiment Involving Tri-Met’s Automated Bus Dispatching System

  An operations plan contains information on the provision of transit service, including intended service levels, vehicle availability, and driver schedules. Agency resources would be utilized efficiently ...

  Citation × Citation Citation Abstract Copy Title: Bus Transit Operations Control: Review and an Experiment Involving Tri-Met’s Automated Bus Dispatching System Author: Strathman, James G., Kimpel, Thomas J., Dueker, Kenneth Year: 2000 An operations plan contains information on the provision of transit service, including intended service levels, vehicle availability, and driver schedules. Agency resources would be utilized efficiently if the operations plan could be executed without disruptions in service. When service disruptions occur, the aim of operations control is to optimize system performance given the current state of the system (Wilson et al., 1992). This typically involves actions intended to either return service to schedule or restore headways separating vehicles. Disruptions in service impose costs on transit providers in the form of reduced productivity and on passengers in the form of increased in-vehicle travel time, longer waiting time at stops, and greater uncertainty. This paper has two overall purposes. First, it provides a review of operations control principles and practices reported in the literature. Second, it reports the results of an operations control experiment whose objective was to maintain headways, or the time separation between buses on a route. The experiment was developed to explore a possible application of the automated Bus Dispatching System (BDS) recently implemented by Tri-Met, the transit provider for the Portland, Oregon, metropolitan region. Title: Bus Transit Operations Control: Review and an Experiment Involving Tri-Met’s Automated Bus Dispatching System Author: Strathman, James G., Kimpel, Thomas J., Dueker, Kenneth Year: 2000 An operations plan contains information on the provision of transit service, including intended service levels, vehicle availability, and driver schedules. Agency resources would be utilized efficiently if the operations plan could be executed without disruptions in service. When service disruptions occur, the aim of operations control is to optimize system performance given the current state of the system (Wilson et al., 1992). This typically involves actions intended to either return service to schedule or restore headways separating vehicles. Disruptions in service impose costs on transit providers in the form of reduced productivity and on passengers in the form of increased in-vehicle travel time, longer waiting time at stops, and greater uncertainty. This paper has two overall purposes. First, it provides a review of operations control principles and practices reported in the literature. Second, it reports the results of an operations control experiment whose objective was to maintain headways, or the time separation between buses on a route. The experiment was developed to explore a possible application of the automated Bus Dispatching System (BDS) recently implemented by Tri-Met, the transit provider for the Portland, Oregon, metropolitan region. Close