Assessing the Accuracy of Average Travel Speeds from Floating Car Data on Urban Street Facilities

To improve traffic flow on regularly congested roads in a network, the performance of these roads has to be evaluated. The average travel speed is a crucial indicator of traffic quality and is used in several performance evaluation methods. Floating Car Data (FCD) obtained from vehicles equipped with GPS offers continuous and ubiquitous data acquisition, making it a potential alternative to conventional speed detection methods. However, the limited penetration and representativeness of detected vehicles pose challenges. This work investigates the suitability of commercially available FCD for determining accurate space-mean speeds. Ground truth data was collected using Automatic Number Plate Recognition (ANPR), and a comparison analysis was performed with FCD-derived travel times and space-mean speeds. Different statistical measures were applied to evaluate the accuracy of FCD data. The results indicate a generally acceptable correlation between the two data sources, but deviations occur, especially for time intervals with a low number of detected FCD trajectories. Subsequent analyses suggest that a minimum number of five trajectories per hour are sufficient to derive valid space-mean speeds. ... mehrBased on these findings, it is possible to accurately assess the performance of roads exclusively using commercially available FCD.