One method of improving the effectiveness of a bus system is to improve schedule reliability. In evaluating the effect of different strategies to improve reliability, the distribution of bus arrival times in relation to the scheduled arrival times of the buses (adjusted arrival time) is needed. Consequently, an analysis was made to find the distribution of on-time performance. Data were collected from the Milwaukee County Transit System (MCTS) for this study. The results showed that adjusted bus arrival times tend to follow a gamma distribution. This finding differs from the ones that had been proposed in the past. In addition to this finding, adjusted arrival times were examined in relation to the distance along a route, the location of the peak load point, and the headway. Buses in the morning and evening peaks tend to arrive late. However, the midday buses tend to arrive early.
Abstract