Study confirms quality of TomTom traffic data

The Texas Transportation Institute (TTI) has conducted an evaluation of TomTom’s historical traffic data, which confirms that it is a valuable resource as a substitute or complement for other types of highway and arterial traffic measurement data. In the study, the TomTom data was compared to measurements from traffic monitoring systems in Houston. The accuracy evaluation methods used by TTI were consistent with national best practices, specifically, the Guidelines for Evaluating the Accuracy of Travel Time and Speed Data and I-95 Corridor Coalition testing. The two best practices are based on real-time data; however, the evaluation applied similar procedures to historical average data. The benchmark or ‘ground truth’ data used to evaluate accuracy came from two Houston TranStar sources: a toll tag-based traffic monitoring system and a Bluetooth-based arterial street monitoring system. A total of 11 directional segments on US 290 and 18 directional segments on Westheimer Road were used to assess the TomTom data accuracy.

The results demonstrated how closely the TomTom historical data tracks the toll tag and Bluetooth-based benchmark. For US 290, a heavily-congested freeway, the results indicate that average absolute error was less than 5mph on 10 of the 11 directional freeway segments. For Westheimer Road, a major arterial street, the results indicate that average absolute error was greater than on US 290, but was less than 8mph on 17 of the 18 directional segments. The highest error (5.4mph) was in the highest speed category, 31 to 45mph. Ralf-Peter Schäfer, head of TomTom’s traffic product unit, commented, “This evaluation conducted by a highly respected organization in the field, serves as an important reference for us. The validation of speed measurements on both freeways and arterials further proves the quality of our historical traffic data for the United States.”

The TomTom historical traffic database of more than 6 trillion data points provides granular details for more than 40 countries globally. By delivering travel time and speed data for any time of day and day of week from 2008, it can enable government agencies, traffic planning consultancies and other organizations to conduct cost effective analysis that ultimately leads to a better understanding of where improvements in the road network can be achieved.

27 June 2012