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

摘要

In practice, the design of bus routes and stop placement involves calculated trade-offs between service frequency, quality, and access. Increased stop density improves access but contributes to slow operating speeds and increased operating costs. In this thesis, a optimized bus stop spacing model is applied using the high resolution archived stop-level bus performance data from the Bus Dispatch System (BDS) provided by TriMet, the regional transit provider for the Portland metropolitan area. 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 presented using one year's stop-level data from one bus route 19 in Portland, Oregon. The analysis considered both inbound and outbound stop spacing and determined the optimal average stop spacing based on an all-day, peak and off-peak time periods. Based on the analysis considering inbound trips over the entire day, the theoretical optimized bus stop spacing was about 1,200 feet, as compared to the current value of 890 feet. This paper also builds on the all day analysis and focuses on inbound and outbound trips during peak periods, resulting in optimized spacing of about 1,300 feet. The peak hour demand has a significant impact on the transit operation. A bus stop consolidation scheme is proposed for the analyzed bus route considering the peak hour transit demand. Finally, the thesis discusses trade-offs and presents an estimate of transit operating cost savings based on the optimized spacing. Given the growing availability of high-resolution archived data, the thesis 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.