Major construction starts Oct. 3 on US 85 from Highlands Ranch Parkway to C-470

If you are one of the thousands of daily drivers on US 85 (South Santa Fe Drive) in Highlands Ranch, please give yourself extra time to navigate upcoming construction.

On Monday, Oct. 3, Douglas County and the Colorado Department of Transportation will begin the highly anticipated work to widen and reconstruct 2.5 miles of US 85 from Highlands Ranch Parkway to just north of C-470.

Construction activities will require reduced speeds, lane closures, turn-lane closures, and various full closures.

Drivers should expect to see workers and heavy equipment during the day between 7 a.m. and 7 p.m. with daytime lane closures between 9 a.m. and 3 p.m. weekdays. Overnight lane closures on US 85 and C-470 are expected from 7 p.m. to 5:30 a.m. weeknights.

Please watch for crews, slow down, and avoid distracted driving in the work zone.

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Multimodal Improvements

In addition to widening US 85 from four to six lanes, the project includes the replacement and widening of the existing bridge that carries US 85 over C-470.  Major US 85 intersection improvements will occur at Highlands Ranch Parkway, Town Center Drive, Blakeland Drive, the C-470 interchange ramps, and at County Line Road.

Multimodal improvements include bus stop enhancements, a new shared-use path for bicyclists and pedestrians on the east side of US 85, a below-grade crossing for the C-470 Trail at US 85, a below-grade crossing for the High Line Canal Trail at US 85, and a new pedestrian link from the Wolhurst community to the C-470 Trail.

The project also includes the addition of continuous auxiliary lanes, new asphalt paving, relocation of utilities, raised medians, new curb and gutter, and a new closed storm sewer system with water quality ponds.

Business Access Changes

To increase safety along the vital US 85 Corridor, access to businesses and some streets along US 85 will change to right-in, right-out only. No left turns will be permitted, and traffic will use signalized intersections at Highlands Ranch Parkway, Town Center Drive and Blakeland Drive for all business access.

About the Project

This project is Douglas County’s largest transportation project to date. Project partners include CDOT, the Denver Regional Council of Governments (DRCOG), the Federal Highway Administration, Highlands Ranch Metro District, and Chatfield Basin Developers. Construction is expected to be completed in 2025.

For more information about the upcoming work and to stay up to date on construction impacts, please visit our website,

A safe and accessible multimodal transportation network is one of the Board of County Commissioner’s six core priorities. Read more about the County’s transportation initiatives online.

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