A computer implemented method, apparatus, and computer usable program code for calibrating a speedometer of a vehicle. First information is received by the vehicle from a first radio frequency identification tag. Second information is received by the vehicle from a second radio frequency identification tag. A first measured speed of the vehicle is determined based on a reading from the speedometer and a second measured speed of the vehicle is determined using an elapsed time between when the first information was read and when the second information was read and a predetermined distance. The speedometer is calibrated based on a speed difference between the first measured speed and the second measured speed.