Feasibility of Using Taxi Dispatch System as Probes for Collecting Traffic Information

Using commercial vehicle fleets as probes may be a cost-effective method for obtaining real-time traffic information. Because the taxi dispatch system automatically records the location of a taxi traveling in an urban network, large quantities of real-time travel data can be obtained at low cost. The reliability of this information about real-time traffic conditions, however, has not been investigated. This study examines the feasibility of using taxi dispatch systems as probes for real-time traffic surveillance. The examination focuses on the uncertainties in the data provided by the two types of wireless communications systems—analog and digital Multi Channel Access (MCA)—that are used for dispatching taxis. The study reveals that the digital MCA wireless system is much better than the analog wireless system for data transmission. This article exemplified that selection of longer road segments helps to greatly reduce traffic surveillance errors. Finally, this article discusses the lessons learned from this study and the limitations that must be overcome before the system can be widely deployed.