Diagonal Flyer routes DF1 and DF2 will operate along the CO 119 corridor when BRT service begins

Boulder County, Colo. - The Regional Transportation District (RTD) current Route BOLT between Boulder and Longmont is expanding in 2027 to become a Bus Rapid Transit service. The new ‘Diagonal Flyer’ Bus Rapid Transit (BRT) service will be more reliable, convenient and faster than traditional bus service.

Corridor stakeholders have helped guide the proposed service and frequencies for when Bus Rapid Transit is operational. Customers interested in providing feedback are encouraged to complete a survey regarding how they use, or will use, transit in the corridor (view the RTD news release).

The survey, available through June 30, will help RTD gather input regarding commuter patterns between the cities of Longmont and Boulder as well as along the Diagonal Highway (CO 119). Results of the feedback will help inform the service and schedules for the new Diagonal Flyer route.

Take the RTD Diagonal Flyer Survey

What is Bus Rapid Transit?

Bus Rapid Transit (BRT) is an innovative, high-capacity, lower-cost public transit solution that can achieve the performance and benefits of more expensive rail modes. This service has been designed to transport passengers quickly and efficiently to their destinations, while offering the flexibility to meet a variety of local conditions.

BRT system elements can easily be customized to community needs and incorporate state-of-the-art, low-cost technologies that attract more passengers and ultimately help reduce overall traffic congestion.

About the CO 119 Bus Rapid Transit Project

The CO 119 BRT project will optimize regional connectivity and mobility between Boulder and Longmont by providing improvements that result in faster, safer and more reliable transit travel. The planned Diagonal Flyer Bus Rapid Transit is part of the CO 119 Safety, Mobility and Bikeway Project.

The project includes:

• BRT/queue bypass lanes at signalized intersections along Diagonal Highway
• Improved transit stops in Boulder/Longmont
• Integration with the 119 Bikeway project
• A new Park-n-Ride near US 287 and CO 66 in north Longmont
• Coffman Street busway in Longmont

RTD is partnering with the Colorado Department of Transportation (CDOT) and Boulder County to integrate the CO 119 Bus Rapid Transit project 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.

Map of the Diagonal Highway area showing proposed Bus Rapid Transit (BRT) routes between Boulder and Longmont.