CO 119 Safety, Mobility & Bikeway | Construction Phase

About the 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, delay, tailpipe emissions, and potentially more crashes. The Colorado Department of Transportation (CDOT), the Regional Transportation District (RTD), and Boulder County are taking action to mitigate these outcomes and expand transportation options beyond private automobiles.

The CO 119 Safety, Mobility and Bikeway Project is constructing 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 mode(s) of choice.

Project Facts

  • Program Cost: $165 million
  • Contractor: Kraemer North America
  • Timeline: Fall 2024 to Spring 2027
  • Location: Colorado Highway 119 (CO 119) between Boulder and Longmont
    • Nearest Town/City: Between Boulder and Longmont
    • Mile Point(s): 44.5 to 54.5
    • County: Boulder

Funding has been secured for implementation of the project and a Construction Manager/General Contractor (CM/GC delivery method) will be used to build the project with construction scheduled to start in 2024.

CDOT, RTD, and Boulder County are excited to share details about the improvements coming to CO 119 that will make traveling through the corridor safer for all modes, as well as faster and more reliable for public transit.

Watch the online presentation videos below to learn more about the safety, mobility, and bikeway improvements. Email [email protected] if you wish to receive this presentation in Spanish.

General CO 119 Safety, Mobility & Bikeway Project Updates

Niwot Underpass

Project Area

CO 119 Safety & Mobility Project Map
Map showing the CO 119 Safety, Mobility, and Bikeway Project, highlighting proposed project elements between Boulder and Longmont, Colorado.

Key features include:

  • Bus Rapid Transit (BRT) Stations: Marked with red bus icons along CO 119.
  • Park-n-Ride Locations: Indicated with blue "P" icons at various stations.
  • Operational & Safety Improvements: Shown with green intersection icons.
  • Bus Queue Bypass Lanes: Denoted with a gray bus with a green arrow.

Proposed RTD BRT Routes:

  • Blue Line: Proposed with a 30-minute frequency between Boulder and Longmont, bi-directionally, weekdays and Saturdays: 6 a.m. to 9 p.m. and Sundays 7 a.m. to 7 p.m. Hourly service frequency earlier and later are also proposed to be provided.
  • Orange Line: Proposed with a 30-minute frequency between Boulder and Longmont, bi-directionally, weekdays in the peaks only (6 a.m. to 10 a.m. and 2:30 p.m. to 6 p.m.)
  • Routings of these two patterns will slightly vary within Boulder and Longmont.

Additional features:

  • Intersection reconfiguration at Mineral Road.
  • Northern and Southern Project Limits marked in Longmont and Boulder respectively.

Major roads and highways are also labeled, including Airport Road, Hover Street, Niwot Road, Mineral Road, Lookout Road, Jay Road, CO 52, CO 119, and CO 157.

Project Improvements

  • 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).
  • Physically reconfiguring the CO 52 intersection to improve safety and to accommodate new Bus Rapid Transit (BRT) stations and Boulder County’s Commuter 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.
  • A list of all stops associated with the proposed BRT service is available here.

Project Goals

  • 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.

Project Benefits

  • Vehicles can move through the corridor faster, with shorter wait times at traffic lights, resulting in less fender benders and crashes
  • Traveling the corridor by bus will take about half the time it currently does
  • More frequent bus service supports greater travel flexibility
  • Safer and more comfortable experience accessing the corridor on foot
  • Integration between Bus Rapid Transit, Park-n-Rides, pedestrian crossings, and Boulder County’s Commuter Bikeway enables commuters to switch travel modes safely and reliably

Next Steps and Project Schedule

  • Reviewing and optimizing the proposed design.
  • Planning out the potential phasing of construction.
  • Determining how the design will be packaged for construction.
  • Establishing a schedule for construction.
  • Starting construction in 2024.

Traffic Impacts:

For the week of Sept. 29 – Oct. 5

Construction Impacts

  • A full closure of IBM Drive, from Colorado Highway 119 to IBM E. Loop Road, starts Tuesday, Oct. 1, and will remain closed to all modes of transportation and travel until the end of 2025
  • For alternate access to the business park near IBM Drive, all travelers should follow posted detour signs. Continue traveling southwest on CO 119 and exit at 63rd Street, head north on 63rd Street, turn east to Monarch Road and into the business parking lot
  • Monday, Sept. 30 and Tuesday, Oct. 1, 9 p.m. to 5 a.m., there will be overnight southbound CO 119 single lane closures at IBM Drive/Colorado Highway 52 to shift traffic
  • Tuesday, Oct. 1 to Saturday, Oct. 5, 9 p.m. to 5 a.m., there will be overnight various northbound and southbound CO 119 single lane closures at Jay Road to set barrier and shift traffic
  • Thursday, Oct. 3, 9 p.m. to 5 a.m., there will be an overnight westbound lane closure on Jay Road at CO 119 while crews work in the median to place temporary bikeway paving
  • Saturday, Oct. 5, 9 p.m. to 5 a.m., there will be an overnight northbound CO 119 lane closure at Niwot Road to shift traffic
  • An overnight full closure of Jay Road at CO 119 is expected overnight starting at 9 p.m. Tuesday, Oct. 8, to 5 a.m. Wednesday, Oct. 9. Detour information is coming soon
  • More information is available on the project website. If your usual travel route will be impacted by construction, remember to use Colorado’s public transportation services for or carpool for easier access to and from your final destination
  • In addition, RTD will temporarily close the Niwot Park-n-Ride and permanently close the north- and southbound CO 119 bus stops at CO 52 beginning Sept. 29. Please refer to the RTD press release for more closure details