Construction on the CO 119 bikeway to start in fall 2024 and 63rd Street underpass to become an overpass

The CO 119 Safety, Mobility, and Bikeway Project, a crucial initiative to enhance safety, mobility, and add a bikeway along the CO 119 corridor from Longmont to Boulder, is set to start construction on the bikeway portion in the fall of 2024, with updates provided late summer 2024 according to a Boulder County news release.

The entire project is scheduled from fall 2023 through spring 2027. CO 119, unfortunately, holds the second-highest crash corridor for bicyclists in Boulder County. From 2015 through 2019, there were 17 bicycle crashes, resulting in five severe injuries and one fatality, and since the end of 2019, there have been multiple additional fatalities.

Two important aspects of this project include the 63rd Street intersection and the bikeway connection at Fourmile Canyon Creek trail. Both elements will impact the bikeway's location.

The initial preliminary design showed the 63rd Street intersection with a planned underpass, but late in the design process, a large 24-inch-diameter water line was discovered, which conflicts with the current bikeway layout. According to the project team, the estimated cost to relocate the 24-inch water line is more than $3 million, and it would result in a delay of more than one year for the completion of the bikeway.

The CO 119 Bikeway design team compared the costs of relocating the water line to replacing the underpass with an overpass at the N. 63rd Street intersection. As a result of the study, the team recommended that the planned underpass instead be built as an overpass with grades compliant with ADA and less than 5%.

The design team will formally present this recommendation to the Board of County Commissioners and will ask the Board to amend the application for projects of statewide significance to approve the overpass at the 63rd Street intersection and the new bikeway connection to the Fourmile Canyon Creek trail. The Board's decision will be a crucial step in the project's progress.

Another water line conflicts with the planned bikeway layout near the southern terminus of the bikeway where it intersects the Fourmile Canyon Creek trail. The design team has recommended that the bikeway layout stay in the median and come between CO 119 north and southbound lanes to the Fourmile Canyon Creek trail. The option includes a bridge over Fourmile Canyon Creek that would be within the two to five-year floodplain and require an occasional detour using Jay Road and 4th Street to avoid a flooded bikeway. The design team plans to make the detour well-marked, so bikeway users will know when the detour route should be taken.