VEHICLE WIRING SYSTEM, OPTICAL COUPLER, AND METHOD OF CONSTRUCTING VEHICLE WIRING SYSTEM

A vehicle wiring system includes a plurality of functional units to be mounted in a vehicle, an optical transmission line that is wired between the functional units and configured to transmit an optical signal of the functional units, an electric wire harness that is provided, in a partial section of the optical transmission line, together with the optical transmission line in a state of being integrated with the optical transmission line, and an optical coupler that is disposed in a portion of the optical transmission line other than the section and constitutes a part of the optical transmission line.