An effort to widen a key stretch of Interstate 25 from Castle Rock to Monument south of Denver has received a $65 million boost that state and local officials have said is a key piece of funding for the project.

And the Colorado Department of Transportation also is getting $25 million from the feds to add an additional 12-mile shoulder lane on Interstate 70 in Clear Creek County.

The I-25 widening will receive the $65 million grant from the U.S. Department of Transportation’s Infrastructure for Rebuilding America (INFRA) program, CDOT spokeswoman Tamara Rollison confirmed Tuesday.

CDOT has proposed adding a pair of toll lanes to the 18-mile stretch, widening it from two to three lanes in each direction. Residents have said adding toll lanes to the stretch, known as the Gap, would amount to double taxation and would not ease traffic jams except for those who pay the toll.

Officials have said that construction could begin on the $350 million project later this summer if all other funding is secured. Local and state officials have identified funding sources – including state transportation funds that a new law is expected to generate and local contributions from Douglas and El Paso counties – to foot the rest of the bill.

Both of Colorado’s U.S. senators hailed the two grants in a joint statement Tuesday.

“I’m thrilled to announce Colorado will receive $90 millionfor critical infrastructure projects in our state,” said Sen. Cory Gardner, R-Colorado. “Coloradans who commute on South I-25 every day or utilize I-70 to travel to the Western Slope and experience the beautiful public lands Colorado has to offer are all too familiar with the unbearable traffic on Colorado highways. These projects will help alleviate congestion on South I-25 and I-70 and help improve the lives of every Coloradan who travels our roads.”

“Colorado’s infrastructure requires significant investment to keep pace with the enormous growth of new residents and tourists,” said Sen. Michael Bennet, D-Colorado. “These grants will help make improvements to the critical links Coloradans use every day to reach the high country and Southern Colorado.”

Gardner and Bennet said sent letters in support of these grants in October 2017.