The National Highway (part of the National Land Transport Network) is a system of roads connecting all mainland states and territories of Australia, and is the major network of highways and motorways connecting Australia's capital cities and major regional centres.

History

Legislation National funding for roads began in the 1920s, with the federal government contributing to major roads managed by the state and territory governments. However, the Federal Government did not completely fund any roads until 1974, when the Whitlam government introduced the National Roads Act 1974.. Under the act, the states were still responsible for road construction and maintenance, but were fully compensated for money spent on approved projects.

In 1977, the 1974 Act was replaced by the State Grants (Roads) Act 1977, which contained similar provisions for the definition of "National Highways"..

In 1988, the National Highway became redefined under the Australian Land Transport Development (ALTD) Act 1988, which had various amendments up to 2003. The 1988 Act was largely concerned with funding road development in cooperation with the state governments. The federal transport minister defined the components of the National Highway, and also a category of "Road of National Importance" (RONI), with federal funding implications. Section 10.5 of the Act required the state road authorities to place frequent, prominent, signs on the National Highways and RONI projects funded by the federal government.

In 2005, the National Highway became the National Land Transport Network, under the AusLink (National Land Transport) Act 2005. The criteria for inclusion in the network was similar to the previous legislation, but expanded to include connections to major commercial centres, and inter-modal facilities. All of the roads included in National Land Transport Network as of 2005 were formally defined by regulation in October 2005. The Minister for Transport may alter the list of roads included in the network. Three amendments to the scheduled list of roads have been made, in February 2007, September 2008 and February 2009. The third variation, published in February 2009, is current as of September 2012.

Under AusLink a program that operated between July 2004 and 2009, the AusLink National Network had additional links, both road and rail. The Federal Government encouraged funding from state, territory and local governments and public–private partnerships to upgrade the network and requires state government funding contributions on parts of the network, especially for new links. For example, the Pacific Highway and the Calder Highway are part of the National Network, yet new projects are being funded 50/50 by federal and state governments. State contributions (generally 20%) are required on some sections of the old network near major cities.

Roads and routes The various superseded Acts defined National Highways as roads, or a series of connected roads, that were the primary connection between two State or Territory capital cities, as well as between Brisbane and Cairns, and between Hobart and Burnie. The term "Sea Highway" is sometimes used colloquially to describe the sea lines of communication between the state of Victoria on the Australian mainland and island state of Tasmania across the Bass Strait.

The of roads included in the original National Highway system had large variations in road quality. Some sections were no more than dirt tracks, whilst others were four lane dual carriageways. While was sealed, there was also worth of gravel roads. The National Highway was gradually improved, with the sealed proportion increased from 73 per cent in the early 1970s to 88 per cent by 1981. The sealing works were completed in 1989.

Since 2005, National Highways were no longer defined in federal legislation. However, the routes were marked with a National Highway route marker up until 2013. These markers have "NATIONAL" printed in the upper portion of the shield, above the highway's number. The shield, text and number are coloured yellow while the background is dark green – the national colours of Australia. In 2014, the route makers retained the national colours, although the word "NATIONAL" was removed in the Australian Capital Territory, New South Wales, and parts of both Queensland and Victoria.

National Highway numbering originates from the earlier national route network. Many of the routes that are now National Highways with the signature green and gold shields, continue beyond the official National Highway as the black and white shielded national routes. Certain stretches of the National Highways have "A" and "M" tag on their shields; particularly those in Victoria and South Australia. They have completely revised their route numbering, basing it on the British M, A, B, C classifications. These states have retained the original National Highway numbering and shield decal, having added the appropriate M and A classification.

List of roads on the National Land Transport Network

Sydney to Melbourne – Hume Motorway/Hume Highway/Hume Freeway Sydney to Brisbane – the Pacific Motorway (Sydney–Newcastle), New England and Cunningham Highways route and the Pacific Highway route Brisbane to Cairns – Bruce Highway Brisbane to Darwin – Warrego, Landsborough, Barkly and Stuart Highways Brisbane to Melbourne – Warrego, Gore, Newell and Goulburn Valley Highways and Hume Freeway Melbourne to Adelaide – Western Freeway, Western Highway, Dukes Highway and South Eastern Freeway Adelaide to Darwin – Port Wakefield Road, Augusta Highway and Stuart Highway Adelaide to Sydney – Sturt and Hume Highway/Hume Motorway Adelaide to Perth – Port Wakefield Road, Augusta Highway, Eyre, Coolgardie-Esperance (part) and Great Eastern Highways Perth to Darwin – Great Northern, Victoria and Stuart Highways Sydney to Canberra – Hume Motorway/Hume Highway and Federal Highway Melbourne to Canberra – Hume Freeway/Hume Highway and Barton Highway Hobart to Burnie including the link from Launceston to Bell Bay – Brooker, Midlands and the Bass Highway Townsville to Mount Isa – Flinders Highway Melbourne to Sale – Princes Highway Perth to Bunbury – South Western Highway Melbourne to Mildura – Calder Highway Sydney to Dubbo – Great Western and Mitchell Highways Sydney to Wollongong – Princes Motorway and Princes Highway Melbourne to Geelong – Princes Highway some urban links in Sydney, Melbourne, Brisbane, Perth and Adelaide, connecting the long distance links to each other and to ports and airports.

Former National Highway routes The following roads were part of the original National Highway network. Most are still signposted with National Highway route markers. In 2013, New South Wales introduced a new alphanumeric route numbering system, which no longer includes national highways.

Route Former route Road name Destinations Distance (km)Canberra to Sydney: A23 National Highway 23 Federal Highway Canberra to ACT/NSW border 73 M23 National Highway 23 NSW/ACT border to Yarra M31 National Highway 31 Hume Highway/Hume Motorway Yarra to Sydney 187260 kilometresCanberra to Melbourne: A25 National Highway 25 Barton Highway Canberra to ACT/NSW border 52 A25 National Highway 25 NSW/ACT border to Yass M31 National Highway 31 Hume Highway Yass to Albury 294 M31 National Highway (M)31 Hume Freeway Wodonga to Melbourne (Thomastown) 290 M80 National Highway M80 Western Ring Road Melbourne 15651 kilometresSydney to Melbourne: M31 National Highway 31 Hume Motorway/Hume Highway Sydney to Albury 539 M31 National Highway (M)31 Hume FreewayWodonga to Melbourne (Thomastown) 290 M80 National Highway M80 Western Ring Road Melbourne 15844 kilometresSydney to Adelaide: M31 National Highway 31 Hume Motorway/Hume Highway Sydney to Tarcutta 392 A20 National Highway 20 Sturt Highway Tarcutta to Buronga 597 A20 National Highway (A)20 Mildura to Hewett 370 Gawler Bypass Hewett to Willaston 3 M2 National Highway M20 Northern Expressway Willaston to Waterloo Corner 23 A1 National Highway (A)1 Port Wakefield Road Waterloo Corner to Adelaide 131,403 kilometresSydney to Brisbane: M1 National Highway 1 Pacific Motorway Sydney to Newcastle 127 A43 National Highway 15 New England Highway Newcastle to Belford 581 A15 Belford to Wallangarra National Highway (A)15 Wallangarra to Warwick 95 Cunningham Highway Warwick to Yamato 127 M15National Highway 15 Yamanto to Riverview M2Ipswich Motorway Riverview to Wacol 14 M7 Wacol to Brisbane944 kilometresMelbourne to Brisbane: M80 National Highway M80 Western Ring Road Melbourne 15 M31 National Highway (M)31 Hume Freeway Melbourne (Thomastown) to Seymour 75 M39 National Highway (M)39 Goulburn Valley Freeway Seymour to Shepparton 59 A39 National Highway (A)39 Goulburn Valley Highway Shepparton to Tocumwal 110 National Highway 39 Newell Highway Tocumwal to Goondiwindi 1062 National Highway (A)39 Leichhardt Highway Goondiwindi to North Goondiwindi 21 National Highway 85/A39 Gore Highway North Goondiwindi to Toowoomba 202 A2National Highway 54/A2Warrego Highway Toowoomba to Brassall 97M2 Brassall to IpswichNational Highway 15Ipswich Motorway Ipswich to Wacol 14 M7 Wacol to Brisbane1,655 kilometresMelbourne to Adelaide: M80 National Highway M80 Western Ring Road Melbourne 15 M8 National Highway (M)8 Western Freeway Melbourne (Deer Park) to Ballarat 115 A8 National Highway (A)8 Western Highway Ballarat to VIC/SA border 314 Dukes Highway SA/VIC border to Tailem Bend 189 A1 National Highway (A)1 Princes Highway Tailem Bend to Murray Bridge 25 M1 National Highway (M)1 South Eastern Freeway Murray Bridge to Adelaide 74719 kilometresAdelaide to Darwin: A1 National Highway (A)1 Main North Road Adelaide to Gepps Cross tba Port Wakefield Road Gepps Cross to Waterloo Corner tba Port Wakefield Highway Waterloo Corner to Port Wakefield tba Augusta Highway Port Wakefield to Port Augusta tba A87 National Highway (A)87Stuart Highway Port Augusta to SA/NT border tba National Highway 87 NT/SA border to Daly Waters tba National Highway 1 Daly Waters to Darwin tba3,035 kilometres Perth to Adelaide: National Highway 94 Great Eastern Highway Perth to Redcliffe tba Great Eastern Highway Bypass Redcliffe to Hazelmere tba Roe Highway Hazelmere to Midvale tba Great Eastern Highway Midvale to Coolgardie tba Coolgardie–Esperance Highway Coolgardie to Norseman tba National Highway 1 Eyre Highway Norseman to WA/SA border tba A1 National Highway (A)1 SA/WA border to Port Augusta tba Augusta Highway Port Augusta to Port Wakefield tba Port Wakefield Highway Port Wakefield to Waterloo Corner tba Port Wakefield Road Waterloo Corner to Gepps Cross tba Main North Road Gepps Cross to Adelaide tba2,700 kilometresPerth to Darwin:National Highway 95 Roe Highway Midvale (Perth) to Middle Swan (Perth)Great Northern Highway Middle Swan (Perth) to Port HedlandNational Highway 1 Port Hedland to Wyndham Victoria Highway Wyndham to Katherine Stuart Highway Katherine to DarwinBrisbane to Darwin: M7 National Highway 15 Ipswich Motorway Brisbane to Wacol 14M2 Wacol to RiverviewNational Highway 54/A2Warrego Highway Riverview to BrassallA2 Riverview to Morven National Highway 71/A2Landsborough Highway Morven to BarcaldineNational Highway 66/A2 Barcaldine to CamoowealBarkly Highway Cloncurry to CamoowealNational Highway 66 Camooweal to Tennant CreekNational Highway 87Stuart Highway Tennant Creek to Daly WatersNational Highway 1 Daly Waters to DarwinBrisbane to Cairns: M1 National Highway (M)1Bruce Highway Brisbane to Kybong A1 National Highway (A)1 Kybong to CairnsHobart to Burnie:National Highway 1 Brooker Highway Hobart to Granton 17 Midland Highway Granton to Launceston 177 Bass Highway Launceston to Burnie 142336 kilometres

History of changes to Australia's National Highway network