With the electrification of suburban networks, which began in 1919, a consistent electric rail traction standard was not adopted.

The four km long Flinders Street to Sandridge line was opened by the Melbourne & Hobson's Bay Railway Company at the height of the Victorian gold rush.

Mainline electrification was first carried out in Victoria in 1954, closely followed by New South Wales which continued to expand their network.

These networks have fallen into decline, in contrast to Queensland where 25 kV AC equipment was introduced from the 1980s for coal traffic.

Most units were of local design and construction, using imported British or American technology and power equipment.

The three major firms were Clyde Engineering partnered with GM-EMD, Goninan with General Electric, and AE Goodwin (later Comeng) with the American Locomotive Company (ALCO).

The major British company was English Electric, with Swiss firm Sulzer also supplying some equipment.

The Australian Rail Track Corporation (ARTC) is a federal government owned corporation established in 1997 that owns, leases, maintains and controls the majority of main line standard gauge railway lines on the mainland of Australia, known as the Designated Interstate Rail Network (DIRN).

In 2003 the Australian and New South Wales Governments agreed that ARTC would lease the NSW interstate and Hunter Valley networks for 60 years.

As part of this agreement, ARTC agreed to a $872 million investment programme on the interstate rail network.

Funding is focused on the National Network, including the following rail corridors, connecting at one or both ends to State Capital Cities: After the 2007 federal election, the government body Infrastructure Australia was created to oversee all rail, road, airports and other infrastructure at a national level.

Construction and maintenance of network infrastructure is consolidated into non-profit government bodies and contracted private: in the case of the interstate network and various non-urban railways of New South Wales, Victoria and Western Australia, the Australian Government-owned Australian Rail Track Corporation (ARTC); the New South Wales Regional Network, John Holland Rail; and rail infrastructure throughout the southern half of Western Australia, Arc Infrastructure.

ARTC intends to start discussions with Queensland about leasing this track once the NSW arrangements are bedded down".

Other railways continue to be integrated, although access to their infrastructure is generally required under National Competition Policy principles agreed by the Federal, State and Territory governments: Inland Rail is a railway construction project extending from Melbourne to Brisbane along a route west of the Great Dividing Range.

[citation needed] Wider gauges were sometimes used as well; Queensland had a number of 991 mm (3 ft 3 in) systems, some on wooden rails.

In the early 21st century, the disused Queensland Rail line to Esk 1,067 mm (3 ft 6 in) in the Brisbane Valley was used for timber haulage.

These lines are continually optimising axle loads (currently the heaviest in the world) and train lengths, that have pushed the limit of the wheel to rail interface and led to much useful research of value to railways worldwide.

[15] An open access sixth standard gauge iron ore network was proposed to the Oakajee Port in the Mid-West region to the south of the Pilbara but the project is currently on hold pending a viable business case.

High speed rail has been repeatedly raised as an option since the 1980s, and has had bipartisan support for research and land purchase.

Following an extensive consultation period with industry, governments and unions, a final version of the national legislation was submitted to and approved by the Transport Ministers in November 2011.

[34] The Rail Safety National Law was first enacted in South Australia in 2012 and all other states and territories have either adopted the RSNL or passed legislation that models it.

This legislation created the Office of The National Rail Safety Regulator (ONRSR), based in Adelaide.