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
- Project Design Exhibits
- Roadway typical section shown below:

Public Meetings
- Previous Public Meetings
- Virtual Public Meeting – Aug. 24, 2021
- View the Aug. 24, 2021 public meeting (PASSCODE = +w3e&v^M)
Project Timeline
- Design – 2021 (COMPLETE)
- Construction anticipated to begin in April 2026
- Construction ends in December
Project Contact
- Andrew Barth, Public Works Communications Manager – abarth@bouldercounty.gov or 303-441-1032
Existing Conditions


Project Area Map

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