Boulder County, Colo. - Beginning at 5 a.m. on Wednesday, June 3, through 5 p.m. on Saturday, June 6, CO 52 will be temporarily closed to all traffic between CO 119/Diagonal Highway and 71st Street.

This closure is required to connect CO 52 to the realigned CO 119 and switch the signals and railroad crossing over to the new alignment. as part of the CO 119 Safety, Mobility and Bikeway Improvements Project.

During the closure, motorists will be directed to follow signed detour routes. There will not be a separate signed detour for cyclists. Cyclists are strongly encouraged to use an alternate route while the closure is in place.

Detour: For alternate access, travelers should use US Highway 287 (via Ken Pratt Boulevard in Longmont or Colorado Highway 7 in Boulder) to detour around the closure.

Work schedules are subject to change and can vary based on conditions. View the CDOT Traffic Update for May 31 to June 6 for more CO 119 construction impacts and closures.

Temporary Closure of CO 52 Between CO 119 and 71st Street detour map.

View the CDOT CO 119 Safety, Mobility & Bikeway page for more information.

Subscribe to CO 119 Diagonal Highway Safety, Mobility and Bikeway Project Construction Updates from CDOT.

Project Contacts

CO 119 Safety, Mobility and Bikeway Project Area Map.

Boulder County wants to ensure that everyone has equal access to our programs, activities, and services. To request an Americans with Disability Act (ADA) accommodation, please email ada@bouldercounty.gov, or call 303-441-1386. If you need help in another language, please email cppfrontdesk@bouldercounty.gov or call 303-441-3930.