To provide an on-vehicle composite unit capable of avoiding complexity of various type wirings and assuring a carrying space in an automobile in the case of carrying various equipment used for a GPS, a VICS or an ETC.

A single unit 5 is integrally constituted by receivers 1, 2, 3 of an artificial satellite positioning system GPS and a road traffic information system VICS and a transceiver 4 of a superhigh way toll automatic payment system ETC. Signal processors of the GPS, the VICS and the ETC are built in a car navigation apparatus 7, and a display unit 6 of the apparatus 7 is commonly used at the GPS, the VICS and the TETC. One multiconductor line 8 for conducting both information transmission and power source voltage transmission is connected from the unit 5 to the apparatus 7.