Driver information and motorist aid hardware

The state of the art of three types of driver information and motorist aid hardware is presented: variable message signing (VMS), highway advisory radio (HAR), and motorist aid systems (MAS). The evolution of this hardware is discussed as well as the current practices and future direction. This is not intended to be an exhaustive discussion but rather a summary and critique of these hardware types. In conclusion, some interim steps are identified that are and can be taken before a total integrated driver information and motorist aid system can be implemented.