The purpose of the Road Automobile Communication System (RACS) is to provide a total communication means to the running automobile. This report summarizes the optic systems of RACS. Firstly the paper explains the optical system for communication system for tunnel. After that the optical system for process automation of vehicle identification is defined. When the above system configuration is established a nationwide overall data communication system can be supported using a pair of frequencies. The optical system has been deigned to offer a maximum flexibility. The modular design allows further expansion as demand increases by the addition of extra modules.