The installation of the first span of Super T girders on the viaduct of the Toowoomba Second Range Crossing (TSRC) project is now complete.

"The installation of the viaduct's first 11 girders (span) is a major achievement. This sounds like a normal bridge job, but not when you consider the work is happening on the steep side of the Toowoomba Range and these Super Ts are up to 38 metres long, weighing up to 90 tonnes each," Queensland Minister for Main Roads and Road Safety Mark Bailey, who visited the site this week, said.

"The viaduct is being constructed along the escarpment between Wallens Road at Ballard and the New England Highway, using 5000 tonnes of reinforcement and 26,000 cubic metres of concrete.

"Completion of the first span means viaduct construction can now progress without affecting the rail line and Nexus can move on to pouring the bridge deck that will carry four lanes of traffic."

Federal Member for Groom John McVeigh also visited the site to inspect progress.

"The viaduct is really starting to take shape on the city's northern edge, with the first 11 of 242 massive concrete girders installed at Mount Kynoch," Dr McVeigh said.

"This process will continue until the 22 spans are complete, alternating between Super T girder installation and concrete pours."

Construction of the bridge deck will take approximately two years to complete.

The Toowoomba Second Range Crossing project provides an alternative crossing of the Toowoomba Range for all classes of vehicles and hazardous goods transport to the north of Toowoomba, approximately 41 kilometres in length, running from the Warrego Highway at Helidon in the east, to the Gore Highway at Athol in the west.

The TSRC project is being funded on an 80:20 basis by the Australian and Queensland governments.