The Colorado Department of Transportation announced on April 1 that the Oxford Road median between northbound and southbound Colorado Highway 119, also known as the Diagonal Highway, will be closed to all modes of transportation beginning at 7 a.m. on Thursday, April 9. The closure is expected to last about one month and is part of the ongoing CO 119 Safety, Mobility and Bikeway Improvements Project.
The closure aims to allow crews to construct a raised bikeway crossing and widen the road for extended deceleration lanes. Officials said local access will be maintained for property owners near the construction area, but through access via the Oxford Road median will not be available during this period.
Motorists traveling westbound are advised to pass Oxford Road, continue northbound on CO 119, turn left onto Airport Road’s median, then turn left onto southbound CO 119 before turning right onto Oxford Road. Eastbound motorists and cyclists should turn right onto southbound CO 119/Diagonal Highway, then left at Niwot Road’s median before accessing northbound CO 119.
According to project planners, closing the median entirely for a month was chosen over shifting barriers and traffic flow around operations for several months. This approach is intended to minimize overall impacts at the intersection during construction work.
By the year 2040, traffic along Diagonal Highway between Boulder and Longmont is projected to increase by approximately twenty-five percent. Increased traffic could lead to more congestion and delays as well as higher emissions and crash risks. The improvements project seeks to address these concerns by enhancing safety features throughout the corridor while making transit travel faster and more reliable.
Planned upgrades include new signage and striping at pedestrian crossings with improved signal timing at key intersections such as Jay Road, Niwot Road, Airport Road, Colorado Highway 52, and others. A commuter bikeway with local connections between both directions of CO 119 is also planned along with reconfigured intersections designed for safer travel conditions.
According to the official website of the Colorado Department of Transportation (CDOT), CDOT works statewide on integrated transportation solutions that improve quality of life in Colorado (official website). CDOT oversees infrastructure including interstates and state highways while supporting aviation grants (official website). Shoshana Lew serves as executive director according to CDOT’s official website.
Construction schedules may change depending on conditions. For updates or questions regarding this project or detour routes during closures or lane shifts along Diagonal Highway/CO 119 throughout its duration residents can visit codot.gov/projects/co119-mobility.
