Arc Infrastructure (previously known as Brookfield Rail and WestNet Rail) is a transport infrastructure manager and access provider in Western Australia with a long-term lease on the network from the Government of Western Australia.

It operates approximately 5,500 km of standard, narrow and dual gauge rail infrastructure in the southern half of the state.

In December 2000, the State Government privatised Westrail, with the Australian Railroad Group, a 50/50 joint venture between United States rail operator Genesee & Wyoming and Australian rural services company Wesfarmers, the successful bidder.

[5] On 1 June 2006, Australian Railroad Group was sold with the above rail rolling stock and terminal assets passing to QR National, and the below rail infrastructure business to Babcock & Brown Infrastructure.

[15][16] Arc Infrastructure has a lease until 2049 on 5,500 kilometres (3,400 mi) of rail infrastructure throughout the southern half of Western Australia, from Geraldton in the north, to Leonora and Kalgoorlie in the east, and south to Esperance, Albany and Bunbury.