Abstract: A travel detecting apparatus is disclosed which generates a pulse signal in response to vehicle motion and detects the actual rate of vehicle travel in accordance with the pulse signal. The apparatus comprises a speed or RPM sensor coupled to an automotive transmission for generating a first pulse signal representative of the vehicle speed or RPM, a tire-size setting switch for setting tire information relating to the dimensions of the tires of the vehicle, and a CPU for frequency converting the first pulse signal in response to the tire information to generate a second pulse and for detecting the rate of vehicle travel in accordance with the second pulse signal.