Eyre Highway is a highway linking Western Australia and South Australia via the Nullarbor Plain. Signed as National Highways 1 and A1, it forms part of Highway 1 and the Australian National Highway network linking Perth and Adelaide. It was named after explorer Edward John Eyre, who was the first European to cross the Nullarbor by land, in 1840–1841. Eyre Highway runs from Norseman in Western Australia, past Eucla, to the state border. Continuing to the South Australian town of Ceduna, it crosses the top of the Eyre Peninsula before reaching Port Augusta.
The construction of the East–West Telegraph line in the 1870s, along Eyre's route, resulted in a hazardous trail that could be followed for interstate travel. A national highway was called for, with the federal government seeing the route's importance in 1941, when a war in the Pacific seemed imminent. The highway was constructed between July 1941 and June 1942, and was trafficable by January 1942. It was originally named Forrest Highway, after John Forrest, by the war cabinet. It was officially named Eyre Highway, a name agreed upon by the states' nomenclature committees.
The finished road, while an improvement over the previous route, still was not much more than a track, and remained such throughout the 1940s and 1950s. Efforts to seal the highway began in Norseman in 1960, with the Western Australian section completed in 1969 and the South Australian section finished in 1976. Further improvement works have been undertaken since the 1980s, including widening and reconstructing portions of the road.
Route description
Eyre Highway is the only sealed road linking the states of Western Australia and South Australia.
Eyre Highway is part of the National Highway route between Perth and Adelaide, and forms part of Australia's Highway 1. It is signed as National Highway 1 in Western Australia, and National Highway A1 in South Australia. The vast majority of the highway is a two-lane single carriageway Road trains (A-double or B-triple) up to are permitted on the Eyre Highway, with Quads up to 49.5 metres (163 feet) between Ceduna and Colona Station turnoff limited to .
The Western Australian section of Eyre Highway is on the western side of the Nullarbor Plain. The South Australian section crosses the eastern section of the Nullarbor Plain, and the top of the Eyre Peninsula. The Nullarbor gets its name from Latin for "no tree". The typical view on the route is a straight highway and practically unchanging flat saltbush-covered terrain. The Eyre Peninsula has been extensively cleared for agriculture, although there are remnant corridors of native eucalyptus woodland alongside its roads.
Main Roads Western Australia and the Department for Infrastructure & Transport in South Australia monitor traffic volume across the states' road networks, including various locations along Eyre Highway. In Western Australia, the recorded traffic volumes ranged between 430 and 760 vehicles per day in 2013/14.
Safety
thumb|The Eyre Highway crosses the flat terrain of the [[Nullarbor Plain]]
In 2011, the Australian Automobile Association considered the Eyre Highway to be among the lowest risk highways in the country, based on total number of casualty crashes