Practical approach for travel time estimation from point traffic detector data

This article presents a practical approach for estimating travel times by using point traffic detector data. The authors stress that accurate estimation of travel time is critical to the success of advanced traffic management systems and advanced traveler information systems (ATIS). Travel time estimation is considered an important performance measure of the transportation system. The authors review a number of methods to address the three major issues associated with travel time estimation from point traffic detector data: imputing missing or inaccurate data, speed transformation from time-mean speed to space-mean speed, and travel time estimation that converts the speeds recorded at detector locations to travel time along the highway segment. They present case study results to show that the spatial and temporal interpolation of missing data and the transformation to space-mean speed can improve the accuracy of the estimates of travel time. They conclude that the piecewise constant-acceleration-based method developed in this study and the average speed method produce better results than the other three methods proposed in previous studies. They recommend that these methods be compared with travel time estimation methods that use traffic flow models under varying traffic conditions.