Method for the Annual Accuracy Assessment of Freeway Travel Time Systems

Motivated by Title 23 Code of Federal Regulation 511, the U.S. Department of Transportation has recently established real-time systems management information programs to improve the consistency of traveler information provided to the public. Part of these requirements is to review the quality of the information provided to the public. Because limited information is available about current practices for meeting this new regulation, this article presents a method of evaluating real-time travel time information along metropolitan interstate freeways in the context of 23 CFR (Code of Federal Regulations) 511. This article presents a method and a case study of collecting travel time information from multiple sources (such as Google Maps and TravelMidwest.com ) and comparing them to measure accuracy. The findings suggested that the travel time information in the Chicago, Illinois, metropolitan area meets the accuracy requirements of 23 CFR 511, and this study has identified areas for future improvement and system expansion.