The disclosed subject matter relates to a vehicle identification system comprising a central station, a roadside reader for wirelessly communicating with radio tags carried by vehicles, a mapping unit connected to the reader, and a correlation unit connected to the mapping unit, wherein the correlation unit is configured to correlate second-protocol tag identifications to first-protocol tag identifications from a reserved subset of first-protocol tag identifications, wherein the mapping unit is configured to generate a new first-protocol message upon receiving a second-protocol message from the reader, and wherein the central station is configured to receive and store first-protocol messages from the reader as well as new first-protocol messages from the mapping unit and to identify a vehicle. The disclosed subject matter further relates to a method for identifying vehicles by means of this system.