This paper deals with the problem of estimating the current traffic situation on a road network in a metropolitan area. The traffic situation can be described by different parameters; the cur-rent travel time on the roads between major intersections is one of them. The travel time is a main criterion for route choice in a road network, for private as well as for commercial users. However, travel times on metropolitan area roads are subject to strong fluctuations due to the variability of traffic demand and lots of interference like traffic lights. Conventional stationary detectors observe traffic flow and local speed at certain locations of the road network and therefore are hardly able to provide reliable and area-wide travel time estimations. An alternative approach is the use of floating car data (FCD). Experiences from three years of research in this technique by the authors are described in this paper. Beside research in the field of obtaining, processing and analyzing FCD the activities also include the development of some prototypical mobility services based on FCD, which are described in the second part. (Author/publisher)
Abstract