Great Northern Highway

Great Northern Highway is an Australian highway that links Western Australia's capital city Perth with its northernmost port, Wyndham. With a length of almost 3,200 kilometres (2,000 mi), it is the longest highway in Australia, with the majority included as part of the Perth Darwin National Highway. The highway, which travels through remote areas of the state, is constructed as a sealed, predominantly two-lane single carriageway, but with some single-lane bridges in the Kimberley. Economically, it provides vital access through the Wheatbelt and Mid West to the resource-rich regions of the Pilbara and Kimberley. In these areas, the key industries of mining, agriculture and pastoral stations, and tourism are all dependent on the highway.

In Perth, the highway begins in Midland near Great Eastern Highway, and further north intersects the Reid and Roe highways, which together form Perth's ring road. There are also three rural highways that spur off Great Northern Highway. Brand Highway and North West Coastal Highway provide an alternative coastal route between Muchea and Port Hedland, while Victoria Highway carries the National Highway route and interstate traffic into the Northern Territory. Various road routes are allocated to sections of Great Northern Highway, including the Highway 1 routes National Route 1 and National Highway 1, as well as National Highway 95.

The highway was created in 1944 from existing roads in the Wheatbelt and a series of tracks through remote pastoral areas. However, it was a hazardous route that could be dusty in the dry season, and boggy or washed away in the wet season. Some sections were effectively impassable sand, while others contained limestone outcrops. Economic growth and development in northern Western Australia prompted initial improvement efforts, and the federal government's Beef Roads Scheme in the 1960s resulted in a noticeably higher-quality road in the Kimberley. Construction of a sealed road from Perth to Wyndham, including numerous bridges to reduce the impact of seasonal flooding, took many years to complete. The last section opened on 16 December 1989, and received national media coverage. However, by then many older sections were either worn out or not up to modern standards. Various upgrades have been carried out in small sections, across the length of the highway, with further works planned. The southernmost part of the highway, from Midland to Muchea, was bypassed in 2020 by the NorthLink WA project that upgraded and extended the Tonkin Highway to Muchea. This section remains in use for local traffic and tourism to the Swan Valley area.