Road traffic information using a dedicated radio beacon

Abstract

Traffic information is available on national and local FM radio throughout Europe. Dedicated motorway FM radio frequencies exist in some European countries. Radio traffic information limited coverage areas also exist in different countries. In this article, we present, develop and evaluate a radio beacon that instantly delivers traffic information to oncoming drivers over communication ranges several hundred meters in distance. This beacon uses a low power co-channel repeater to achieve a single isofrequency seamless communication network. The proposed local beacon effectively overrides the network-wide signal for a targeted road segment. The beacon is operated over large audience frequencies. The aim of this beacon is to deliver emergency information to drivers, using the existing unmodified car radios. No particular action is necessary for the car drivers to receive the alert information transparently. To enhance the beacon effectiveness, Radio Data System (RDS) and RDS Traffic Message Channel (RDS–TMC) services are also supported. This particular Vehicle to Vehicle communication system is intended to work as a complementary means to existing optical driver information systems. The FM radio beacon objectives are described and some initial on site measurements are performed to define the beacon technical requirements. The theoretical concept of the beacon is detailed and some associated laboratory measurements used to validate its working mode are provided. A technical description of a prototype equipment assembly is presented. Results obtained during experimentation campaigns along a motorway network are analyzed.