Great Northern Highway is the main north-south route between Perth and the northern areas of Western Australia. Covering a distance of , it is the longest highway in Australia. From Midland in Perth's north-east, the highway heads generally north-east through the Wheatbelt and Mid West to Newman, north-west to the coastal Pilbara town of Port Hedland, along the coastline to Broome, east to Halls Creek, and finally north to Wyndham, on the state's northern coastline. out from Wyndham, the highway intersects the start of Victoria Highway, which carries interstate traffic to the Northern Territory via Kununurra. Various road routes are allocated to sections of Great Northern Highway, which is mostly a National Highway route, and also forms part of Australia's Highway 1. It is signed as National Route 1 from Midland to Middle Swan, National Highway 95 and National Route 1 concurrently from Middle Swan to Muchea, National Highway 95 from Muchea to Mundabullangana, and National Highway 1 from Mundabullangana to Victoria Highway. The vast majority of the highway is a two-lane single carriageway, although there are thirteen single-lane bridges and four single-lane floodways in the Kimberley. The speed limit is except in and around built up areas.