Temporary closure of CO 52 between CO 119/Diagonal Highway and 71st Street scheduled for May 6 to 9

News Release

May 1, 2026 - Northeastern Colorado - Closure required to connect CO 52 with realigned CO 119/Diagonal Highway

Boulder County - Colorado Highway 52 will be closed to all traffic between Colorado Highway 119/Diagonal Highway and 71st Street beginning at 5 a.m. on Wednesday, May 6, through 5 p.m. on Saturday, May 9. This closure is part of the CO 119 Safety, Mobility and Bikeway Improvements Project and is required to connect CO 52 to the realigned CO 119.

During the closure, motorists will be directed to follow signed detour routes. There will not be a separate signed detour for cyclists. Cyclists are encouraged to use an alternate route while the closure is in place.

Detour: For alternate access, travelers should use US Highway 287 (via Ken Pratt Boulevard in Longmont or Colorado Highway 7 in Boulder) to detour around the closure.

Detour and closure map for CO 52 from CO 119 to 71st Street
The map illustrates the full road closure of CO 52 between CO 119 and 71st Street from May 6 to May 9, 2026, featuring a detailed zoom-in inset of the primary work zone and clearly marked detour routes via US 287 and Ken Pratt Boulevard.

Realigning CO 52 at CO 119/Diagonal Highway will improve mobility in the intersection and along the corridor. To minimize impacts to travelers, the project team decided to temporarily close CO 52 between CO 119 and 71st Street. The alternative would be continuously shifting barriers and traffic flow around the work for several weeks, causing longer disruptions at the CO 52 and CO 119 intersection.

Work schedules are subject to change and can vary based on conditions. 

What is the CO 119 Safety, Mobility and Bikeway Improvements Project?

By the year 2040, the Diagonal Highway between Boulder and Longmont is expected to see a 25% increase in vehicular traffic. Increased traffic can result in more congestion, delays, tailpipe emissions and potentially more crashes.
The CO 119 Safety, Mobility and Bikeway Project is constructing safety, mobility and bikeway improvements to make traveling through the corridor safer for all modes and transit travel faster and more reliable. The project is designed to integrate with other active multimodal projects on the corridor to ensure community members can safely and reliably travel throughout the corridor using their preferred mode(s) of transportation.

This project will:

  • Improve safety in the whole corridor.
  • Maximize the number of people able to move through the corridor.
  • Maximize intersection operational efficiency.
  • Improve transit travel times and increase ridership.
  • Maximize corridor-wide operational efficiency.
  • Increase opportunities for bicycle commuting and connectivity to the bicycle and pedestrian network.

Specific corridor improvements include:

  • New signage, striping and improved signal timing at all pedestrian crossings at signalized intersections.
  • Signal timing adjustments at key intersections (Jay Road, 63rd Street, CO 52, Niwot Road and Airport Road).
  • Adding a commuter bikeway and several local connections between northbound and southbound CO 119, and underpasses or overpasses at major intersections for uninterrupted crossing.
  • Physically reconfiguring the CO 52 intersection to improve safety and to accommodate new Bus Rapid Transit (BRT) stations and the Diagonal Bikeway between the northbound and southbound travel lanes.
  • Changing access at Airport Road and CO 119 to reduce crashes and improve safety and traffic flow.

During construction, CO 119/Diagonal Highway will largely remain configured as it currently operates, with various lane shifts and closures. Additional information will be provided prior to any major closures or detour routes throughout the project duration. In addition, lane and shoulder widths will be minimized. The speed limit will be reduced. Please pay attention and follow posted speed limits. Kraemer North America is the General Contractor for this project.

Project contact information

  • Project phone line: 720-378-8083
  • Project email: [email protected]
  • Project website: codot.gov/projects/co119-mobility
  • Sign up for weekly project updates on the project website by following these five simple steps:
    • Visit the project website.
    • Select on the "Stay Informed" box on the right side of the page.
    • From there, scroll to the "Construction Updates & News Releases" section and select "Subscribe to Construction Updates".
    • Enter your email address, then select "Northeast Colorado" as the region, check "Front Range I-25 Corridor" and "CO 119 Safety & Mobility Improvements."
    • Scroll to the bottom and select the "Submit" button

Know Before You Go

Travelers are urged to “know before you go.” Gather information about weather forecasts and anticipated travel impacts and current road conditions prior to hitting the road. CDOT resources include:

Remember: Slow For The Cone Zone

The following tips are to help you stay safe while traveling through maintenance and construction work zones.

  • Do not speed in work zones. Obey the posted speed limits.
  • Stay Alert! Expect the unexpected.
  • Watch for workers. Drive with caution.
  • Don't change lanes unnecessarily.
  • Avoid using mobile devices such as phones while driving in work zones.
  • Turn on headlights so that workers and other drivers can see you.
  • Be especially alert at night while driving in work zones.
  • Expect delays, especially during peak travel times.
  • Allow ample space between you and the car in front of you.
  • Anticipate lane shifts and merge when directed to do so.
  • Be patient!

Download the COtrip App!

The free COtrip Planner mobile app was designed to meet the growing trend of information on mobile and tablet devices for the traveling public. The COtrip Planner app provides statewide, real-time traffic information, and works on mobile devices that operate on the iOS and Android platforms. Visit the Google Play Store (Android devices) or the Apple Store (iOS devices) to download!