Floating Car Data (FCD) fleets are a valuable data source to obtain travel times as basis for traffic information or route guidance systems. To deliver reliable traffic information and to improve algorithms and systems for generating FCD from GPS positions their current quality has to be evaluated first. In this contribution the travel times from actual vehicle trips are compared with travel times for each edge on those trips as they result from the FCD algorithm. About 540,000 trajectories generated by more than 4,000 taxis at four Wednesdays in October 2010 are the basis for this comparison.