Roadside radio system for broadcasting on expressway

In Japan, as road vehicles become more popular as transportation media and the roads improve, the percentage of transportation relying on vehicles has been increasing constantly and this increasing trend continues For this reason, a new emphasis is being placed on the accurate and rapid supply of traffic information as well as improvement of road networks. The roadside radio system was developed to respond to these requirements of the age. This system is characterized by the following features. • Supply of traffic information automatically edited by computers. • Voice output by the synthesizer which has 24-channel multiplex output. • Information supply from 24 individual medium-wave radio stations respectively to 24 broadcasting zones at a transmitting frequency of 1,620 kHz. • Use of a special cable antenna to minimize radio interference into adjacent broadcasting zones as well as other radio broadcasts.