Denver

Diagonal Highway Transformation: Boulder to Longmont Commute Set for Safety and Mobility Overhaul

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Published on September 12, 2025
Diagonal Highway Transformation: Boulder to Longmont Commute Set for Safety and Mobility OverhaulSource: Google Street View

The road gets a revamp, and the commuters of Boulder County are in for some significant updates. In an ongoing bid to enhance the travel experiences between Boulder and Longmont, a comprehensive project is taking shape along the Diagonal Highway. The CO 119 Safety, Mobility & Bikeway Improvements Project, as it's known, aims to transform the corridor into a paragon of transportation efficiency and safety.

According to Boulder County, the collaboration muscle is strong with Commuting Solutions, Boulder County, the City of Boulder, the City of Longmont, RTD, and CDOT flexing their partnership to bring this vision to life. At the heart of the project is a dual thrust: a separated, 9-mile bikeway kitted out with branded wayfinding signs and the kickoff of a swift Bus Rapid Transit service.

Taking a cue from its environs, the project's branding exhales the Front Range's natural splendor into a user-friendly navigation system. "Our goal with the new branding and wayfinding system is to create a cohesive and user-friendly experience for all travelers along CO 119," said Audrey DeBarros, Executive Director of Commuting Solutions, as per Boulder County. Signs will don the blue and gold hues, a visual echo of the acclaimed Flatiron Flyer brand, to maintain a consistent regional identity.

The community has been front and center in the project's development. Via online surveys attuned to both English and Spanish speakers and pop-up events, locals have injected their preferences for a contemporary, yet uncomplicated design. The road's bikeway has been christened the Diagonal Bikeway, while the soon-to-zoom BRT service will carry the name Diagonal Flyer. These elements, as told by the county, affirm the area's unique sense of identity and are set to shape the CO 119 corridor into something more than a mere stretch of pavement.

Denver-Transportation & Infrastructure