Urban traffic analysis from a large scale floating car data system

The actual knowledge of traffic performances and travel patterns existing in an urban area is crucial to quantify the effects of transportation improvements and of actions that have to be pursued to improve mobility, as well as even an essential input to calibrate land use and traffic simulation models. In this view the use of Floating-Car Data (FCD) is emerging as a reliable and cost-effective way to gather accurate traffic data for a wide-area road network and to improve the analysis of travel conditions. The purpose of this paper is to provide an insight into the potential application of wide scale FCD for improving the traffic analysis process. The reliability of traffic estimates from FCD largely depends not only on the accuracy but also on the size of the input data: until now FCD experiments have been carried out with few equipped vehicles, maximum some dozen; moreover, mostly of them were special vehicles like taxi or bus, with preferential routes, so their behaviour cannot be taken as general reference. The originality of this study lies in the large number of private-owned cars involved corresponding to a penetration rate of about 1.3 percent. A full day of FCD related to the city of Florence is examined in this paper to estimate some travel related measures that cannot be readily replicated on a dayby-day basis using other data sources such as user surveys.