Many urban service systems have the need to estimate travel times between arbitrary points on the highway network. Some of these systems, such as Dial-a-Ride, require these estimates to be performed in real time. This paper describes and evaluates various computerized methods for performing these estimates. This paper begins by considering the characteristics on estimating techniques. Some experimental data are presented. Then various models for travel time estimation are described and evaluated using the City of Cambridge, Mass., as a test case. A framework for travel time prediction is established along with a characterization of the various errors inherent in the techniques. Tradeoffs between accuracy of the estimate, speed of the estimating procedure, and computer storage requirements are presented.
Abstract