The highway originally bore the name Monaro Highway until 1958, when it received its current name. It originally ran from Tathra to Wagga Wagga but has been shortened to run from the Princes Highway to the Hume Highway instead. Part of the roadway was reallocated to what is now known as the Monaro Highway in 1955. Reservoirs created as a result of dams built in the 1950s and 1960s as part of the Snowy Mountains Scheme required the creation of major realignments to avoid submerged areas. Previous to New South Wales' conversion to alphanumeric route markers, it was signed as National Route 18.