Highway advisory radio

In 1977, two years after its initial Notice of Proposed Rule Making in Docket 20509, the Federal Communications Commission (FCC) authorized the establishment of travelers\´ information stations (TIS) in the Local Government Radio Service, Part 90 of the FCC Rules and Regulations. Stations may he authorized on either 530 kHz or 1610 kHz for the purpose of providing useful noncommercial information to the traveling public by agencies of state and local governments via the AM radios with which most motor vehicles are currently equipped. Agencies of the federal government, such as the U.S. Park Service, have also been authorized by the Interagency Radio Advisory Committee (IRAC) to operate travelers information stations subject to the same rules adopted by the FCC. The background of highway advisory radio (HAR) and some of the considerations that led to the present rules are discussed. The effect on HAR system design of limitations imposed by the rules and by AM receiver characteristics is also discussed. Using field data acquired under a Federal Highway Administration (FHWA) contract, the problems of HAR antenna design within the FCC imposed limits are illustrated. Finally, the FCC "Part 15" alternative to the design of HAR systems is discussed. Conclusions are stated. The general conclusion drawn is that HAR can be, and has repeatedly proven to have been, a useful tool for traffic management and control.