May 21, 2026
Media Contact
Andrew Barth, 303-441-1032
Full Closure of 120th Street Starts Tuesday
Closure in place through October
Boulder County, Colo. - Starting at 7 a.m. next Tuesday, May 26, 120th Street will be closed to all travelers between the south entrance to Rock Creek Circle and Dillon Road for approximately five months. The closure is necessary due to the significant earthwork required to complete the roadway safety improvements project. The current road will be completely removed and rebuilt.
Roadway Improvements
Construction will widen the road to accommodate two five-foot paved shoulders with two-foot painted buffers that will help separate shoulder users, like bikes and pedestrians, from motor vehicle travel. The additional shoulder width will also provide room for disabled vehicles and emergency responders. Work will include flattening some of the steep hills to reduce fuel use and noise from large trucks that frequently travel this road and eliminate blind spots. In addition, a northbound lefthand-turn lane will be added at the northernmost Rock Creek Circle intersection to improve safety. Safety improvements to the bridge over Northwest Parkway in the City and County of Broomfield are also planned. The project will tie into the improvements the City and County of Broomfield have already completed at the Dillon Road intersection.
For more information on the project and to see a map of the project area, visit www.BoCo.org/120TH or email Andrew Barth, Public Works Communications, at abarth@bouldercounty.gov or call 303-441-1032.

