Floating-car data (FCD) are recorded by probe vehicles equipped with Global Navigation Satellite System (GNSS) receivers. The importance of this data category grew significantly during the last years, presently replacing the stationary detector data as the “workhorse” for navigation and traffic management applications. Accurate speeds from those geo-positions can be derived from map matching to a digital map. Extended floating-car data as a sub-category includes additional information collected by specially equipped vehicles, smartphone sensors or cameras. In contrast to trajectory data and stationary detector data, floating-car data represent only a sample. Extensive quantities such as traffic flow and density cannot be measured directly but require additional information or modeling.