Highway 1 continues around the rest of Australia, joining all mainland state capitals, and connecting major centres in Tasmania.

At Lake Clifton, Old Coast Road takes Highway 1 north along the coastline to Halls Head, south of Mandurah.

[2] Due to the onset on World War II, supply roads leading to the north of the Australia were considered vital.

[7][8] A bi-weekly mail route from Boyanup to Bridgetown via Preston, Balingup, and Greenbushes was established by 1891; it also extended further south to Balbarrup on a weekly basis.

[9] Surveying of a direct Bridgetown–Albany route was requested in January 1871, so that an electric telegraph line could be established, but the government surveyors were overwhelmed by other work.

By October 1921, £16,000 had been spent on upgrading the dirt track to a formed and gravelled road, with works expected to be completed over the 1921–22 summer at a cost of £2,000.

[13] The settlement of Australind by the Western Australian Land Company in 1840–41 prompted the first real need for a good quality road to Perth.

Brand Highway began as part of a network of roads between Dongara and Gingin, as a result of increased development in the area.

This allowed native wildflowers to survive and flourish on public land, providing aesthetically pleasing and interesting views to reduce road hypnosis and driver fatigue.

[15] North West Coastal Highway was created in 1944 from existing roads and tracks through remote pastoral areas.

Economic growth and development in northern Western Australia prompted initial improvement efforts in the late 1940s, and a sealed road was constructed from Geraldton to Carnarvon by 1962.

The impact of cyclones and seasonal flooding resulted in a realignment inland of the Carnarvon to Port Hedland section, which was constructed and sealed between 1966 and 1973, and required thirty new bridges.

Great Northern Highway was created in 1944 from existing roads in the Wheatbelt, and a series of tracks through remote pastoral areas.

Construction of a sealed road from Perth to Wyndham, including numerous bridges to reduce the impact of seasonal flooding, took many years to complete.

Originally a series of unformed tracks linking pastoral holdings, the route was developed as a gravel road in the 1950s to aid the beef industry.

Improvements took place in the 1960s which tied in with the development of the Ord Irrigation Scheme, which enabled the introduction of road trains.