About: Highway 1 (South Australia)

In South Australia, Highway 1 is a 1,715-kilometre (1,066 mi) long route that follows the coastline of the state, from the Victorian border near Mount Gambier to the Western Australian border near Eucla. Highway 1 continues around the rest of Australia, joining all mainland state capitals, and connecting major centres in Tasmania. All roads within the Highway 1 system are allocated a road route numbered M1, A1, B1 or R1, depending on the state route numbering system. In South Australia, most of the highway is designated as route A1, with multi-lane, dual-carriage-way sections generally designated route M1, and the alignment around the Adelaide CBD designated route R1. South-east of Tailem Bend, it is designated route B1.