Probe vehicle data;  PVD;  Vehicle tracking data

Floating car data (FCD) refers to using data generated by one vehicle as a sample to assess the overall traffic condition (“cork swimming in the river”). Typically this data comprises basic vehicle telemetry such as speed, direction and, most importantly, the position of the vehicle.

The over-time-collected positional data component of FCD is referred to as vehicle tracking data. FCD can be obtained by tracking using either GPS devices or mobile phones. The latter type results in low-accuracy data. Depending on the collection method and data accuracy, more or less sophisticated map-matching algorithms have to be used to relate tracking data to a road network.

In database terms, the tracking data can be modeled in terms of a trajectory, which is obtained by interpolating the position samples. Typically, linear interpolation is used as opposed to other methods, such as polynomial splines. The sampled positions then become the endpoints of line segments and the movement of an object is represented by an entire polyline in 3D space.

FCD is a powerful means to assess traffic conditions in urban areas given that a large number of vehicles collect such data. Typical vehicle fleets comprise taxis, public transport vehicles, utility vehicles, but also private vehicles.