For information about Boulder County Ballot Measures, visit the county’s Ballot Measures website.

Boulder County government offices, except the Elections Division, closed Nov. 3 for Election Day.

120th Street Reconstruction

120th Street Shoulders Project - Overlook Drive to Dillon Road

Project Completed – Road open as of 2 p.m. on Monday, Oct. 26

Background

Boulder County, in partnership with the City of Lafayette, is planning to reconstruct 120th Street between Overlook Drive in the City of Lafayette and Dillon Road in the City and County of Broomfield. Construction will widen the road to accommodate two five-foot paved shoulders with two-foot painted buffers to separate out shoulder users from vehicular traffic. The project will also flatten some of the extreme grades of the area’s hillsides to reduce energy use by the numerous large trucks and other vehicles that are currently using the road which will help reduce noise and fuel consumption.

Critical Project Issues and Needs

  • Reconstruct 1.25 miles of 120th Street with new profile and pavement to improve drainage and reduce steep grades
  • Widen pavement to 36-feet to allow for a vehicle lane in both directions along with two seven-foot buffered shoulders
  • Add a northbound left-turn lane to the northern Rock Creek Circle intersection to improve safety
  • Match the road width and striping of the 2021 City and County of Broomfield improvements at the Dillon Road intersection.

Design Exhibits

120th Street shoulders project roadway typical section

Public Meetings

Project Timeline

  • Design – 2021 (COMPLETE)
  • Construction anticipated to begin in April 2026
  • Construction ends in December

Project Contact

Existing Conditions

120th Street Reconstruction project - Existing conditions looking north

120th Street Reconstruction project - Existing conditions looking south

Project Area Map

120th Street Shoulders Project Area Map

Boulder County aims to ensure all digital content and documents are accessible. While efforts have been made to maximize accessibility, some types of content have inherent technical limitations. For alternate formats or accommodations, please submit an ADA Web Accommodation Request Form or email ada@bouldercounty.gov, or call 303-441-1386. View the county’s accessibility statement.

Contact Us

Public Works

303-441-3900
Submit a request
tdadmin@bouldercounty.gov

Location

2525 13th St.
Boulder, CO 80304

Hours: Building Open 8 a.m. - 4:30 p.m.
Tuesdays and Thursdays

Mailing Address

P.O. Box 471
Boulder, CO 80306