East Colfax Avenue Bus Rapid Transit

Colfax Avenue carries more bus riders than any other street in Colorado, and it has never had a lane of its own. The $280.4 million East Colfax Bus Rapid Transit project changes that across roughly 10 miles, running from Union Station east through Denver to Colfax Station at Interstate 225 in Aurora. As of May 2026, with the Aurora segment groundbreaking, construction is active across all five segments at once.

Project Scope

Kraemer North America is delivering the work under a CM/GC contract, with Sky Blue Builders providing vertical construction on the BRT stations and architectural elements. The design puts dedicated bus lanes in the center of the roadway rather than at the curb, which removes the conflict with right-turning traffic and parked cars that slows curb-running bus lanes to walking pace. Stations sit in the median with level boarding, and signal priority is being built into the corridor’s traffic control.

The construction problem is that Colfax stays open. Crews are rebuilding pavement, drainage, utilities and traffic signals under live traffic and live bus service along a street lined with small businesses that depend on street frontage, which is why the corridor was broken into five segments with staged closures rather than a single long shutdown. RTD approved a separate $66.9 million purchase of 47 New Flyer 60-foot articulated buses to run the line.

Why It Matters

Center-running BRT is the format that actually delivers rail-like travel times without rail capital cost, and very few U.S. cities have built it on a legacy commercial corridor rather than a highway median. Colfax is a hard version: narrow right-of-way, historic frontage, dense curb demand and no easy detour route.

Revenue service is expected in January 2027. The project has been recognized by the Institute for Sustainable Infrastructure through its Envision framework. If the travel-time savings hold up on a street this constrained, it becomes the reference case that other mid-size transit agencies point at when they argue for taking a general-purpose lane.

Project Team & Details