The route connecting the West and East coasts of the South Island via the Southern Alps were known for hundreds of years by the Māori people, due to a flourishing pounamu trade.

A route connecting Christchurch to Hokitika was fully completed in 1866, with the first Cobb & Co coach began operating that same year for the burgeoning gold rush.

Construction of a rail link had started in 1890, and the Midland Line between Canterbury and the West Coast was finally completed on 4 August 1923, with the opening of the Otira Tunnel.

As a result, numerous studies were conducted into alternative options for fixing the road around Candy's Bend, Starvation Point and the Zig Zag.

After peaking, the road descends into Arthur's Pass village with the railway line emerging from the Otira Tunnel nearby.

After Springfield, the road emerges onto the Canterbury Plains and runs straight through the settlements of Annat, Sheffield and Waddington before arriving at Darfield.

The road then passes through the settlements of Kirwee, Aylesbury and West Melton as well as dairy and lifestyle farms characteristic of the plains.

In the early years SH 73 originally ended at the Blenheim Road and Hansons Lane corner in Upper Riccarton.

In 2014, the entire highway has been revoked due to completion of the Christchurch Southern Motorway (gazetted SH 76 in 2012) which runs almost parallel to this route.