Travelers' information station
A travelers' information station (TIS), also called highway advisory radio (HAR) by the United States Department of Transportation, is a licensed low-powered non-commercial radio station, used to broadcast information to the general public, including for motorists regarding travel, destinations of interest, and situations of imminent danger and emergencies.
"[1]Most TIS/HAR licenses in the U.S are held by governmental entities, in addition to quasi-governmental agencies and authorities as well as health and emergency service providers working in conjunction with the government.
Also, during a widespread electrical outage stations equipped with reserve battery or generator power can continue operating, for reception by battery-operated radios.
However, an alternate implementation, called "leaky cable", is a form of carrier current transmission, which employs long horizontal conductors, commonly run alongside roadways.
Stations using a standard antenna are generally limited to a coverage radius of 1.9 km (1.2 mi), with an antenna height of no more than 15 m (49 ft), and a maximum power of 10 watts, although special events and critical evacuation systems, such as those in the Florida Keys and near chemical and nuclear facilities, have been granted waivers to exceed that limit, typically for up to 100 watts.
On July 18, 2013, in response to petitions submitted from Highway Information Systems, Inc. (HIS), the American Association of Information Radio Operators (AAIRO), and the American Association of State Highway and Transportation Officials (AASHTO), the FCC adopted Report and Order 13-98 updating and clarifying the regulations applying to TIS stations.
The Report and Order, as summarized by a May 2014 Compliance Guide (DA-14-651), approved the establishment of "ribbons" of sequentially located roadside transmitters so long as content remained pertinent at all points.
State and local governments may also create state-wide networks to provide non-commercial public safety information via radio using LPFM stations.
In Germany and the former Yugoslavia, highways and motorways are provided with traffic information by radio, although the original systems have been largely replaced.
[13] The radio station operates on low-power antennas along Presidente Dutra Highway, between São Paulo and Rio de Janeiro, on 107.5 MHz, and airs information about traffic and news.
Between 2004 and 2018, Radiovia Freeway FM, a TIS station operated on 88.3 MHz, was also on the air along the BR-290, between Porto Alegre and the northern coast of Rio Grande do Sul.
