Assessment of an Optimal Bus Stop Spacing Model Using High Resolution Archived Stop-Level Data

With increasing attention being paid to performance and financial issues related to the operation of public transportation systems, it is necessary to develop tools for improving the efficiency and effectiveness of service offerings. With the availability of high resolution archived stop-level bus performance data, it is shown that a bus stop spacing model can be generated and tested with the aim of minimizing the operating cost while maintaining a high degree of transit accessibility. In this paper, two cost components are considered in the stop spacing model including passenger access cost and in-vehicle passenger stopping cost, and are combined and optimized to minimize total cost. A case study is conducted using one bus route in Portland, Oregon, using one yearrs stop-level archived Bus Dispatch System (BDS) data provided by TriMet, the regional transit provider for the Portland metropolitan area. Based on the case study, the theoretical optimized bus stop spacing is 1,200 feet compared to the current value of 950 feet. The paper discusses trade-offs and presents an estimate of transit operating cost savings based on the optimized spacing. Given the availability of high resolution archived data, the paper illustrates that this modeling tool can be applied in a routine way across multiple routes as part of an ongoing service planning and performance measurement process.