The U.S. Department of Transportation has approved a $386 million loan to help the N.C. Turnpike Authority finance construction of the $1 billion, 18.8-mile Triangle Expressway, a toll road through Research Triangle Park and western Wake County.

"This project will go a long way toward serving the travel needs of commuters in key educational and employment centers in this important region," Ray LaHood, the U.S. transportation secretary, said in a press release.

The turnpike authority expects to sell $615 million in bonds to raise the rest of the money, which would be repaid from toll collections. Construction is expected to begin in early August.