Traffic shift and intersection closure on CO 7 (Arapahoe Avenue) in Boulder starting next week

Travel Advisory

Sept. 12, 2025 - Northeastern Colorado - Long delays anticipated, alternate routes highly advised for weekend intersection closure Sept. 19 to 22

Boulder County – Next week, traffic will shift to a one-lane traffic pattern in each direction on the eastbound lanes of Colorado Highway 7 (Arapahoe Avenue) between Foothills Parkway and Range Street to allow crews to complete work on the westbound lanes safely.

This traffic configuration will be in place through Sept. 22. Access to local businesses will remain open throughout construction, and pedestrians are advised to follow posted detour routes for safe navigation around the work zone.

Beginning Friday, Sept. 19, at 5 p.m. through Monday, Sept. 22, at 5 a.m., the north intersection of CO 7 and 48th Street will be closed for milling and paving operations. A detour will be in place to maintain access to 48th Street. This traffic configuration will remain in effect throughout the weekend.

Detour routes to access Boulder Community Health are provided in the Traffic Impacts below.

Crews will perform reclamation work, removing the existing asphalt and reconditioning base materials to create a stronger foundation, followed by a new asphalt overlay to improve smoothness and safety for drivers. This work is part of an ongoing project to improve roadway conditions and extend pavement life.

Map of detour route for CO 7 and 48th Street closure
Map of detour route for CO 7 and 48th Street closure. Refer to Travel Impacts for details

Travel Impacts

  • Monday, Sept. 15, the westbound traffic pattern will shift to the eastbound lanes. Traffic will remain reduced to one lane in each direction on the eastbound lanes of CO 7 between Foothills Parkway and Range Street
    • Sidewalks and bus stops on the westbound side of the roadway will be closed
      • Detour signs will be posted for pedestrians
  • Friday, Sept. 19, at 5 p.m. through Monday, Sept. 22 at 5 a.m., the north intersection of CO 7 (Arapahoe Avenue) and 48th Street will be closed over the weekend
  • Detour from CO 7 (Arapahoe Avenue) to 48th Street
    • Travel east on CO 7 (Arapahoe Avenue), north on Commerce Street, west through the parking lot, then south on 48th Street
  • Detour from 48th Street to CO 7
    • Travel north on 48th Street, east through the parking lot, south on Commerce Street to connect with CO 7
  • Major delays are expected
  • An alternate route is highly advised
  • Motorists should follow posted detour signs
  • Business access will remain open
  • The speed limit will be reduced to 35 MPH throughout the work zone
  • Please be aware of construction vehicles entering and exiting the work area
  • For current road conditions, visit COtrip.org

Project Contact Information

For additional information about this project, please contact the project team.

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!