Construction underway on the $806 million rebuild of I-270

The I-270 Corridor Improvements project is in construction, according to the Colorado Department of Transportation, with Kiewit Corporation building a reconfigured freeway between Interstate 25 and Interstate 70 through Adams and Denver counties. The corridor carries more than 100,000 vehicles a day, and freight trucks account for nearly 10 percent of that traffic, according to the federal permitting record for the project.

The start of construction follows a six-year environmental review. CDOT and the Federal Highway Administration have published the project's final environmental impact statement and record of decision, which finalizes the selected alternative for roughly six miles of I-270 in Adams County. "I-270 has needed this kind of attention for a long time," CDOT Executive Director Shoshana Lew said in the announcement. "Advancing from an Environmental Assessment to a full EIS in 2023 was the right call."

The rebuild replaces the corridor's 12 aging bridges and adds one tolled Express Lane in each direction alongside two general-purpose lanes in each direction. The Express Lanes will be free for buses, motorcycles and carpools of three or more people. Crews will also rebuild the Vasquez Boulevard interchange, improve ramps at I-76, York Street and Quebec Street, add a continuous auxiliary lane between Vasquez Boulevard and York Street, and widen shoulders with emergency turnarounds to help clear crashes and breakdowns.

The first phase, running from October 2026 into early 2030, raises the westbound roadway along its northern edge on the stretch running from 60th Avenue toward the South Platte River Trail, and rebuilds the eight bridges in the poorest condition, among them the crossings of the South Platte River and the Burlington Ditch and the bridges at Brighton Boulevard and 60th Avenue. The first phase also reconstructs the mainline from the South Platte River to the Vasquez Boulevard ramps. Phases two and three follow from early 2030 to 2033, rebuilding the remaining mainline, the Vasquez Boulevard interchange and the York Street and 56th Avenue bridges, along with the Vasquez Boulevard bridge over Sand Creek, improvements on Sandcreek Drive and a new bicycle and pedestrian overpass.

Away from the travel lanes, the project adds four new RTD bus stops near the Quebec Street interchange, a bicycle and pedestrian bridge between East 56th Avenue and Quebec Street, and air quality monitoring, water quality ponds and wetlands mitigation along the corridor, according to CDOT.

For drivers, the early work is mostly an overnight story. CDOT lists single-lane closures overnight, from 9 p.m. to 5 a.m., on the stretch of I-270 running from 60th Avenue to the South Platte River, plus right shoulder closures on the westbound side of the same stretch and daytime flagging on Brighton Boulevard just north of the freeway. The department lists no daytime impacts on the mainline freeway.