Automated Bus Dispatching, Operations Control, and Service Reliability: Baseline Analysis

Tri-Met, the transit provider in Portland, Oregon, is implementing a new computer-aided bus dispatching system that uses a satellite-based global positioning system to track vehicle location. It is expected that the new system will produce improvements in service reliability. Presented is a baseline analysis of service reliability on selected routes, focusing on running times, headways, and on-time performance. Reliability is found to vary according to route characteristics, direction, and time of day.