Highway advisory radio
Encyclopedia
Travelers Information Radio Stations (TIS), are sometimes also called Highway Advisory Radio Stations (HAR) by Departments of Transportation in the United States. These radio stations are licensed low-power
Low-power broadcasting
Low-power broadcasting is electronic broadcasting at very low power and low cost, to a small community area.The terms "low-power broadcasting" and "micropower broadcasting" should not be used interchangeably, because the markets are not the same...

 AM
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

 radio station
Radio station
Radio broadcasting is a one-way wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both...

s set up by local transport
Transport
Transport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...

 departments to provide bulletin
Bulletin
Bulletin can refer to:Periodicals * The Bulletin, a now defunct Australian magazine* The Bulletin , an alternative weekly published in Montgomery County, Texas, United States...

s to motorists and other travel
Travel
Travel is the movement of people or objects between relatively distant geographical locations. 'Travel' can also include relatively short stays between successive movements.-Etymology:...

ers regarding traffic
Traffic
Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...

 and other delays. These are often near highway
Highway
A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

s and airport
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...

s, and occasionally other tourism
Tourism
Tourism is travel for recreational, leisure or business purposes. The World Tourism Organization defines tourists as people "traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business and other purposes".Tourism has become a...

 attractions such as national park
National park
A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...

s. In the latter case, they often provide a loop of prerecorded information about the park
Park
A park is a protected area, in its natural or semi-natural state, or planted, and set aside for human recreation and enjoyment, or for the protection of wildlife or natural habitats. It may consist of rocks, soil, water, flora and fauna and grass areas. Many parks are legally protected by...

's historic and other background information.

These systems are licensed by the FCC in the United States under 47 CFR Sec. 90.242 and are limited to a maximum signal of 2 mV/m at 1.5 km (0.93 mi) using a power of up to 10 watts to achieve this limit in the case of vertical antenna systems (the most common type). Up to 50 watts in the case of the radiating cable antenna systems may be used to achieve a maximum of 2 mV/m at 60 m (200 ft) from the radiating cable. Radiating cable systems are limited to a continuous antenna length of 1.9 km (1.2 mi). Cable systems are used for situations such as Dulles International Airport with very long limited-access approach roads where multiple systems can be placed in 1.9 km segments. In some cases, such as LAX
Los Angeles International Airport
Los Angeles International Airport is the primary airport serving the Greater Los Angeles Area, the second-most populated metropolitan area in the United States. It is most often referred to by its IATA airport code LAX, with the letters pronounced individually...

 both radiating cable and antenna systems are employed as backup systems for one another.

Critical evacuation systems, such as those in the Florida Keys
Florida Keys
The Florida Keys are a coral archipelago in southeast United States. They begin at the southeastern tip of the Florida peninsula, about south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry...

 and near chemical and nuclear facilities, have been granted exceptional power waivers for emergency operations. These systems will typically operate under the normal power level, but have permission to exceed that limit, typically to 100 W, in the face of a critical emergency evacuation situation.

The audible signal is required to include an audio low-pass filter
Low-pass filter
A low-pass filter is an electronic filter that passes low-frequency signals but attenuates signals with frequencies higher than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a high-cut filter, or treble cut filter...

 which rolls off frequencies above 3 kHz. Content is defined by the FCC as "noncommercial voice information pertaining to traffic and road conditions, traffic hazard and travel advisories, directions, availability of lodging, rest stops and service stations, and descriptions of local points of interest. It is not permissible to identify the commercial name of any business whose service may be available within or outside the coverage area of a Travelers' Information Station. However, to facilitate announcements concerning departures/arrivals and parking areas at air, train, and bus terminals, the trade name identification of carriers is permitted."

In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, only government
Government
Government refers to the legislators, administrators, and arbitrators in the administrative bureaucracy who control a state at a given time, and to the system of government by which they are organized...

s may have licenses for TIS/HAR stations, with some exceptions granted for quasi-governmental agencies and authorities as well as health and emergency service providers working in conjunction with governmental entities. The FCC formerly reserved the bottom and top channels (530 and 1610) on the AM band for these stations, before the Extended AM broadcast band
Extended AM broadcast band
The extended mediumwave broadcast band, commonly known as the [AM] expanded band, is a broadcast frequency allocation which moved the upper limit of the AM bandplan from 1610 to 1700 kHz.- History :...

 (1610 to 1700) was introduced in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Systems may currently be licensed on any frequency from 530–1700 kHz. (Most radios tune to 1710; however, this frequency has only been licensed in one instance, by Information Station Specialists for Hudson County, New Jersey, due to the potential for an evacuation from New York City.)

LPFM stations may be licensed to governments as well, but these are not considered part of the TIS/HAR service. Stations for U.S. national parks and other units under the U.S. federal government are licensed by the NTIA rather than the FCC.

LPFM

In some states, LPFM stations are used to broadcast travelers information. Colorado has a statewide network of LPFMs used in this manner, while many other state, county, or local governments use one or more stations. Examples include WTUS-LP
WTUS-LP
WTUS-LP is a radio station licensed to serve Tuscaloosa, Alabama. The station is owned by the City of Tuscaloosa Travel and Convention Bureau. It airs a Traveller's Information Station format....

 in Tuscaloosa, Alabama
Tuscaloosa, Alabama
Tuscaloosa is a city in and the seat of Tuscaloosa County in west central Alabama . Located on the Black Warrior River, it is the fifth-largest city in Alabama, with a population of 90,468 in 2010...

, operated by the Tuscaloosa Convention and Visitors Bureau; and WGEO-LP
WGEO-LP
WGEO-LP is a low-power radio station broadcasting a News Talk Information format. Licensed to Georgetown, South Carolina, USA, the station is currently owned by City of Georgetown ....

 in Georgetown, South Carolina
Georgetown, South Carolina
Georgetown is the third oldest city in the U.S. state of South Carolina and the county seat of Georgetown County, in the Low Country. Located on Winyah Bay at the confluence of the Great Pee Dee River, Waccamaw River, and Sampit River, Georgetown is the second largest seaport in South Carolina,...

, which is operated by the Georgetown City Fire Department.

Outside of the United States

The concept is not limited to the US: TIS stations operate in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 (on both AM
AM broadcasting
AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is carried out in the medium wave band world wide, and on long wave and short wave...

 and FM
FM broadcasting
FM broadcasting is a broadcasting technology pioneered by Edwin Howard Armstrong which uses frequency modulation to provide high-fidelity sound over broadcast radio. The term "FM band" describes the "frequency band in which FM is used for broadcasting"...

 bands), in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 (at 107.7 MHz FM along selected autoroute
Autoroutes of France
The Autoroute system in France consists largely of toll roads, except around large cities and in parts of the north. It is a network of worth of motorways. Autoroute destinations are shown in blue, while destinations reached through a combination of autoroutes are shown with an added autoroute logo...

s), in Australia in some areas on 87.6–88 MHz FM, and other countries as well.

In Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 Highway Radio broadcasts on 1620 and 1629 kHz AM along stretches of major expressways.

In Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 most highways are covered by RAI
RAI
RAI — Radiotelevisione italiana S.p.A. known until 1954 as Radio Audizioni Italiane, is the Italian state owned public service broadcaster controlled by the Ministry of Economic Development. Rai is the biggest television company in Italy...

's Isoradio
Rai Isoradio
Rai Isoradio is an Italian highway advisory radio service devoted to delivering updated traffic reports and weather reports provided by Aeronautica Militare, public service announcements by various governmental and public organisations, railways information from Ferrovie dello Stato, news...

network, broadcast in most areas on 103.3 MHz.

External links

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