Evaluation of the accuracy and automation of travel time and delay data collection methods

Faghri, ArdeshirTravel time and delay are among the most important measures for gauging a transportation system’s performance. To address the growing problem of congestion in the US, transportation planning legislation mandated the monitoring and analysis of system performance and produced a renewed interest in travel time and delay studies. Current techniques for collecting travel time and delay data range from manual data logging to completely automated, computer-aided record keeping. The techniques employed by the University of Delaware have evolved into a semi-automated system, but human and computer error still have the potential to create inaccuracies. In order to eliminate opportunities for human and computer error, a new GPSbased data collection technique was employed and compared directly with the currently accepted data collection methods. By simultaneously collecting data using three different techniques, the accuracy of the GPS positioning data and the resulting travel time and delay values could be objectively compared for automation and statistically compared for accuracy. It was found that the new technique provided the greatest automation requiring minimal attention of the data collectors and automatically processing the data sets. Using the Analysis of Means, Variances, Wilcoxon Signed Rank Test, and Pearson and Spearman Correlation Analyses, overall results showed that all data collection methods perform equally well for both travel time and delay time measurements.University of Delaware, Department of Civil and Environmental EngineeringM.C.E