Formal Punctuality Analysis of Frequent Bus Services Using Headway Data

We evaluate the performance of frequent bus services in Edinburgh using the punctuality metrics identified by the Scottish Government. We describe a methodology for evaluating each of these metrics that only requires measurements of bus ‘headways’ — the time between subsequent bus arrivals. Our methodology includes Monte Carlo simulation and time series analysis. Since one metric is given in ambiguous language, we provide a formal description of the two most plausible interpretations. The automated nature of our method allows public transport operators to continuously assess whether the performance of their network meets the targets set by government regulators. We carry out a case study using Automatic Vehicle Location (AVL) data involving two frequent services, including the AirLink service to and from Edinburgh airport.