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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.

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.

Tri-Met has implemented an automated bus dispatching system (BDS) employing satellite-based automatic vehicle location (AVL) technology. The BDS is capable of facilitating real-time operations control actions to improve service regularity. This article focuses on a service regularity problem that often occurs during peak periods when regular service is augmented by extra-board trips ("trippers 'J. In this case, "bus bunching" results when regular service trips experience departure delays while trippers depart on schedule. With the aid of BDS information, field supervisors stationed at a key location on Portland s (Oregon) bus mall used holding, short turning, and reassignment actions to maintain headways on six selected routes. Analysis of their efforts reveals an improvement in service regularity as well as a leveling of passenger loads. Operations Control Research To understand how operations control can be effective in reducing variability in system performance, it is first necessary to discuss the causes of unreliable

This paper presents findings from a study assessing the accuracy and precision of automatic passenger counter (APC) technology at Tri-County Metropolitan Transportation District of Oregon (Tri-Met). Video surveillance cameras, rather than ride checkers, were used to establish reference values for determining APC accuracy and precision. Analysis of data collection, processing and reporting methods at Tri-Met indicates that APC data, along with a properly designed sampling plan, can be used for internal monthly ridership reporting and annual National Transit Database (NTD) reporting. Presently, NTD sampling plans require that bus trips be randomly selected prior to manual data collection efforts. The sampling methodology developed for this analysis allows APC data to be matched with a random selection of bus trips following automated data collection.