Electronic_Route_Guidance_System
Electronic Route Guidance System (ERGS) was a 1970s era government sponsored in-vehicle navigation and route guidance system developed by the United States Federal Highway Association.[1] ERGS was the initial stage of a larger research and development effort called the Intelligent Transportation System (ITS).
ERGS was a destination oriented system that required a human driver to enter a destination code into the vehicle system. The vehicle communicated with an instrument intersection where the destination code was decoded and routing information was sent back to the vehicle.[2]
Other international programs included Japan's CACS, which used FR (radio frequency) communication methods, and similar projects in Europe.[1] These programs all used central processing systems with large central computers.[3]