The US Department of Transportation (USDOT) has announced a $501.5m Transportation Infrastructure Finance and Innovation Act (TIFIA) loan for the Complete 540 Project in the Raleigh area of North Carolina.

The loan amount was provided to the North Carolina Turnpike Authority (NCTA) by the Build America Bureau.

US Transportation Secretary Elaine L Chao said: “This $501.5m federal investment in transportation infrastructure in the Raleigh region will promote economic growth while enhancing mobility and reducing congestion for area residents and travellers.”

Under the Complete 540 Project, the Triangle Expressway (Tri-Ex) will be extended by 17.1 miles. Six new toll lanes will be added to the expressway, with three in each direction.

In addition, interchanges with intersecting roads, 55 bridges, 25 box culverts and two stream crossings will be constructed.

Construction will be carried out in three phases. Separate design-build contracts have been awarded to increase the participation of contractors.

Opened in 2013, the Tri-Ex is an 18.8-mile long and six-lane limited-access toll road that has three through travel lanes in each direction. The Tri-Ex secured a $386.66m TIFIA loan in July 2009.

NCTA will repay the majority of the TIFIA loan using money generated from tolls collected on the Tri-Ex System.

Last month, USDOT announced grant awards for major infrastructure projects in Milan and Springfield, Missouri.

This September, USDOT allocated $871.2m to repair roads and bridges damaged by storms, floods and other unexpected events.

The money will be used to rebuild roads in 39 states, as well as American Samoa, Puerto Rico and the US Virgin Islands.