Highway communication system using guidance cable

The guidance cable for automatic driving vehicles can be utilized as a communication medium between the road authority of a highway and vehicles on it. This highway communication system consists of two cables laid along both shoulders of a roadway, two detecting coils attached to the front bumper of a vehicle, and a transmitting-receiving coil mounted on the top of a vehicle. This system enables voice communication between the road authority and road vehicle drivers, and enables a warning to be issued to a vehicle that my swerve from the course.