THE company behind the Toowoomba Second Range Crossing has shared new drone footage of the construction site.

Nexus Infrastructure shared the footage, which features a drone travelling across the entire length of the crossing, to its social media channels on Tuesday. 

The footage comes as several milestones were recently reached on the project.

The last of 522 Super T girders for the viaduct at Mount Kynoch was recently delivered.

Department of Transport and Main Roads regional director Kym Murphy the viaduct was the linchpin of the TSRC because, at 800 metres long, it directly links the summit of the Great Dividing Range and the Lockyer Valley on a relatively flat grade.

Nexus CEO John Hagan said the 1.1km section of Toowoomba-Cecil Plains Road, upgraded as part of an interchange for the Crossing, had reopened to traffic.

"The Toowoomba-Cecil Plains Road interchange will be a key feature for motorists accessing the TSRC from Wellcamp, western Toowoomba and Western Downs regional communities," Mr Hagan said.