Commercial bus speed diagnosis based on GPS-monitored data

Abstract

Commercial bus speed is a key factor in the operation of public transport systems because it represents a direct measure of the quality of service provided to users and also considerably affects system costs. By commercial speed, we are referring to the average speed of buses over stretches, including all operational stops. Evaluating system performance by monitoring the commercial speed provided by bus services is highly desirable; however, in dense networks, it becomes a difficult task because of the amount of information required to implement such a monitoring procedure. The introduction of GPS technology in buses can overcome this difficulty in terms of information availability, although it presents the challenge of processing huge amounts of data in a systematic way. Here, we present a method based on GPS-generated data to systematically monitor average commercial bus speeds. The framework can be applied to each bus route as a whole, as well as over segments of arbitrary length, and can be divided into time intervals of arbitrary duration. The results are presented as matrices and graphs that can be read and interpreted easily. We discuss the potential of this methodology to provide useful insights for bus system planners and operators. The method and its applications are illustrated with data coming from the Santiago-Chile public transport system (Transantiago), where GPS observations of more than 6000 buses operating on over 700 different routes are available every 30 s.