It consists of alphanumeric routes, a one-to-three digit number prefixed with a letter (M, A, B, or C) that denotes the grade and importance of the road,[5] and is now the state's default road route numbering system.
Some also may follow older alignments or routes later changed even after the new system was introduced, and are included here for the sake of completion.
In 1954, the Hume Highway was trialled as National Route 31, chosen due to its prominence as a transport corridor connecting Australia's largest cities (Melbourne and Sydney).
Early in 1964, planning by the Traffic Commission (and consulting with 43 municipal councils and the Country Roads Board),[1] the Metropolitan Route Numbering Scheme – a new route numbering system for the Greater Melbourne area – was unveiled in 1965; Victoria was the first mainland state to adopt this system.
[8] The scheme had a significant refurbishment during the late 1980s:[2] between 1987 and 1990, many existing routes through Melbourne were modified and new routes were introduced (noted in the table below) to cover new growth areas of Melbourne, involving consultation with over 54 metropolitan municipalities as well as road user groups.
After the success of the Metropolitan Route Numbering Scheme across the Greater Melbourne area, an extension of the system was rolled out across regional Victoria from late 1985 as the State Route Numbering System; the South Gippsland Highway was the first road in Victoria signed with a State Route,[3] with others following through 1986[3] and 1987,[2] at an estimated cost of $400,000.
[10] The system lasted just over a decade, before the Statewide Route Numbering Scheme was first introduced in north–eastern Victoria in late 1996.
Most State Routes were converted into the alphanumeric system by 1998, with the rest completed by 2000; none now exist.
After the success of the Metropolitan Route Numbering Scheme across the Greater Melbourne area, a new route number system specifically for suburban freeways was rolled out in 1970, following the opening of the first section of the Tullamarine Freeway.