Assessing a Model for Optimal Bus Stop Spacing with High-Resolution Archived Stop-Level Data

With increasing attention given to performance and financial issues related to the operation of public transportation systems, tools are needed to improve the efficiency and effectiveness of service offerings. High-resolution archived stop-level bus performance data can be used to generate and test a bus stop spacing model with the goal of minimizing operating cost while maintaining a high degree of transit accessibility. Two cost components are considered in the spacing model: passenger access cost and in-vehicle passenger stopping cost. These are combined and optimized to minimize total cost. A case study was made of a bus route in Portland, Oregon, by using I year of stop-level archived data from the Tri-County Metropolitan Transportation District of Oregon, the regional transit provider of the Portland metropolitan area. The case study indicates that the theoretical optimized bus stop spacing is 1,200 ft, compared with the current value of 950 ft. Trade-offs are discussed, and an estimate is presented of transit operating cost savings based on optimized spacing. It is shown that because of availability of high-resolution archived data, this modeling tool can be applied routinely across multiple routes as part of an ongoing service-planning and performance-measurement process.