Two-day closure of North 71st Street at CO 119/Diagonal Highway starts Dec. 15

Travel Advisory

Dec. 10, 2025 - Northeastern Colorado - Daytime closure needed for CO 119 Safety, Mobility and Bikeway Improvements Project

Boulder County — The Colorado Department of Transportation and construction contractor Kraemer North America will require a daytime closure on Monday, Dec. 15, and Tuesday, Dec. 16, for the Colorado Highway 119 Safety, Mobility and Bikeway Improvements Project.

Closure of North 71st Street at CO 119/Diagonal Highway

On Monday, Dec. 15, and Tuesday, Dec. 16, from 7 a.m. to 5 p.m., crews will close North 71st Street between Monarch Road (south of the business park) and CO 119/Diagonal Highway to all modes of transportation. The entrance to the business park on 71st Street will remain open.

For alternate access, those traveling southbound on 71st Street should continue east on Monarch Road to access southbound CO 119.

  • Businesses can access their properties by using Monarch Road, north of 71st Street at CO 119/Diagonal Highway

This closure is required for crews to install light poles. Please use caution in the work zone and follow posted detour signs. 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, Colorado Highway 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 stations and the Diagonal Bikeway between the northbound and southbound travel lanes
  • Changing access at Airport Road and CO 119 to reduce crashes and to 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 notice 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 and the speed limit will be reduced. Please pay attention and follow posted speed limit signs. Kraemer North America is the General Contractor for this project.

CO 119 Safety, Mobility and Bikeway Improvements Project Contact Information

  • Project hotline: 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 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 new 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!