CO 119 rumble strip project starts Nov. 1

Project Update

October 25, 2023 - Northeastern Colorado - Expect delays Nov. 2 and 3 from 9 a.m. to 3 p.m.

Boulder County — The first phase of the safety improvements on CO 119 will begin on Nov. 1 with rumble strips being installed on the outside of the shoulder line from approximately Hover Street in Longmont to Foothills Parkway in Boulder.

The overall project will take 10 working days to complete and will begin with the rumble strips which are expected to be complete by Nov. 3. The machining of the rumble strips will be done during the daytime from 9 a.m. to 3 p.m., utilizing a slow-moving single-lane closure. Traffic delays can be expected.

For those two days (which could also possibly happen during the evening in non-rush times), bicyclists are strongly encouraged to avoid CO 119 because the right lane and the shoulder will be blocked and impassable.

After the strips are in place, the project will add safety signage at intersections to alert drivers to bicyclists in the area. This work is expected to take place Nov. 13-16 and will have sporadic lane and shoulder closures. Bicyclists are strongly encouraged to find new routes during this time as well.

Rumble strips provide an audible and vibration warning to drivers who may be leaving the roadway. The strips will be installed along the edge line of the outside shoulder throughout the corridor where there is adequate space for them to be installed and still allow for cyclists to utilize the shoulders. Rumble strips will not be put in place within 250 feet of any residence or business.

Next spring, the work on the larger aspects of the CO 119 Safety and Mobility Improvements will begin.


By the year 2040, the Diagonal Highway between Boulder and Longmont is expected to see a 25 percent increase in vehicular traffic which can result in more congestion, delay, emissions, and potentially more crashes. The Colorado Department of Transportation and the Regional Transportation District are taking action to mitigate these outcomes and expand transportation options beyond vehicles.

The CO 119 Safety & Mobility Improvements and Bikeway Project will provide improvements to make traveling through the corridor safer for all modes, as well as faster and more reliable for public transit. It will provide critical intersection safety improvements, construct a regional bikeway, and implement Bus Rapid Transit (BRT), connecting the counties of Larimer, Weld and Boulder.

Project improvements include:

  • Pedestrian crossings
    • New signage
    • Striping
    • Improved signal timing
  • Intersections
    • Reconfiguring the CO 52 intersection into a split intersection
    • Safety improvements and access changes to the Airport Road intersection and other non-signalized intersections on the corridor
    • Reconstructing Hover Street intersection
  • Commuter bikeway
    • 9 miles of 12-foot wide concrete path separated from road
    • 6 Underpasses with Pump Stations
    • Grade-separated crossings at major intersections
    • Direct connection to BRT stations and existing bike networks
  • Queue bypass lanes
    • Jay Road
    • CO 52
    • 63rd Street
    • Niwot Road
    • Airport Road
  • Park-n-Rides
    • 63rd Street
    • Niwot Road
  • Bus Rapid Transit stations
    • 63rd Street
    • CO 52
    • Niwot Road
    • Foothills Pkwy/47th Street


Funding has been secured for implementation of the project, which is expected to begin construction in 2024. CDOT, RTD, Boulder County, City of Longmont, and the Denver Regional Council of Governments (DRCOG) have committed $115 million for construction.

Project Partners

CDOT, RTD, Boulder County, City of Boulder, City of Longmont, Commuting Solutions, FHWA, FTA.

Contact Information

For more information, visit the website at: or email [email protected].

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!

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