County Line Road widening advances, traffic shifts and business access changes in Highlands Ranch

Traffic shifts are back on County Line Road as Douglas County crews pushed into noise wall, drainage, concrete and paving work between University Boulevard and Broadway, while access to the Plaza at Highlands Ranch closed between Target and University Boulevard for about three weeks.

The latest changes matter because this stretch carries about 25,000 road users a day and serves Highlands Ranch, Littleton and Centennial. County officials said drivers should expect intermittent single-lane traffic, posted speed limits, flaggers and shifting lanes as the reconstruction moves through new phases. For shoppers and employees trying to reach the Plaza, the county said access remained available through Target or Circle K even as the main entry between those points shut down.

The project has already changed daily travel once. A full closure from Clarkson Street to the U-Haul business access area began in January and lasted about 100 days so crews could import dirt for work at Lee Gulch. County Line Road reopened April 16, but the corridor did not return to normal. Striping, lane widening and remaining noise-wall work were still underway, keeping the road in a state of slow-motion construction rather than a clean reopening.

Douglas County has said the project has been in development since 2019, when final design, right-of-way acquisition and utility-relocation planning began for a major water line in the area. The roadwork broke ground Sept. 12, 2025, with county leaders calling it a multi-jurisdictional effort involving the Denver Regional Council of Governments, the City of Centennial and the City of Littleton.

The county estimates the total construction cost at about $30 million for budgeting purposes, including contingencies, consultant work, inspections and material testing. When finished, the project is expected to add one lane in each direction, install a new traffic signal at Clarkson Street and County Line Road, mill and overlay the Littleton segment between Phillips Avenue and Broadway, and add sidewalks.

The upside is visible, but so is the pain. Wilmore Nursery and Garden Center has said the reduced traffic during the closure hurt business, a reminder that the corridor’s winners and losers are being sorted block by block. Douglas County says the rebuilt road will be safer and more efficient for drivers, pedestrians and local businesses, but that payoff is still being tested by detours, access changes and the unfinished work left ahead.