Bus Arrival Headway Reliability: A Case Study in Hefei, China

摘要

Reliability of transit, as a key measurement in transit operation, is important since it affectsthe mode choice behavior of both current and prospective riders to a great extent, whichimposes direct impacts to transit ridership. Therefore capturing this measurement accuratelyis a key requirement to successfully evaluate whether the transit system is properly operated.However the traditional method of evaluating reliability based on statistical analysis of busarrival headway has several shortcomings. Specifically the value of reliability usingtraditional coefficient of variation (CV) is not between 0 and 1, which makes it difficult toexplain, and the value of reliability can decrease with the increase of the transit headway. Thetraditional method also ignores the fact that buses can arrive at stops as a bunch which meansthe transit service is not reliable. This means the traditional method cannot represent the realoperation condition of transit system. But all these shortcomings can be avoided by using theadvanced method presented in this paper. Also this study establishes an evaluationframework to assess the reliability of the transit system from different stratification, includingstops, routes and network levels. Then the bus operation data of Hefei City is analyzed as acase study. Comparison is conducted to show the improvement made by using the advancedmethod. Based on the new evaluation measurements, an example of adding exclusive buslanes to existing bus route was provided to show how well these advanced method can beused to assess the transit operation and benefit the decision making process.