There are two projects in the works that will transform the future of East Colfax transit services:


15L Route Improvement Project

Over the next several years, RTD will be upgrading all of the 15L stops between Broadway and I-225 to include enhanced shelters with lighting and security cameras. Other improvements such as queue bypass lanes, transit signal priority and bus bulbs will be added in key locations along the corridor.

Learn More About 15L


Colfax Corridor Connections

With support from RTD, the City and County of Denver is leading the Colfax Corridor Connections project which is intended to determine how best to improve transit, overall mobility and livability within the East Colfax corridor over the next 25 years.

Learn More About Colfax Corridor



Providing Transit Enhancements on Colfax

15L Route Improvements – Project Status (as of October 5, 2020)

15L Bus Stop Construction Map

Stops currently under construction pointBus stops currently under construction:

Bus stops with construction planned soon pointBus stop reopened after construction, shelter and amenities will be placed at a later date TBD

Bus stop reopened after construction, shelter and amenities will be placed at a later date TBD pointBus stops with construction planned soon:

Several weeks or months may pass between project phases at each stop.

Download status as PDF

15L Route Improvements Project at a Glance

  • Existing service:
    • RTD routes 15 Local (15) and 15 Limited (15L) serve East Colfax from downtown Denver to the Aurora Metro Center.
    • The 15 and 15L combined are the busiest routes in the entire RTD system, with approximately 24,000 boardings per day, which is more than some RTD rail corridors.
    • Bus service on East Colfax operates nearly 24 hours per day, 7 days a week.
  • The work varies by stop, but will be completed in three general phases:
    1. Initial work may include surveying, erosion control, utility locates, and directional boring.
    2. Crews will continue with site civil improvements that may include replacing concrete bus pads, boarding areas and sidewalks.
    3. The contractor will return to the site to place the bus shelter and amenities.
  • RTD has received grant funds from the Federal Transit Administration (FTA) and the Colorado Department of Transportation (CDOT). 
  • The project will make stop improvements at all 15L bus stops between Broadway in Denver and I-225 in Aurora.
  • The project will connect with the R Line at the Colfax Station on the east end of the route and Civic Center Station on the west end.
  • As part of the project, 37 bus stops will be upgraded.

Bus stops for the 15L are spaced approximately every 1/2 mile along Colfax.

Bus Stop Improvements

  • Enhanced bus shelters that include lighting, security cameras, and passenger information
  • Trash cans and benches

Operational Improvements

  • At some stops, bus bulbs, also know as curb extensions, will be added, which will provide more waiting space for passengers and allow buses to stop in the travel lane instead of pulling to the curb which will reduce delays in service.
  • Queue bypass lanes will be located at four locations where buses experience delays due to traffic congestion. The lanes will allow buses to share a right turn-only lane, which will allow buses to proceed in advance of the green light for the general purpose lanes.
  • Transit Signal Priority (TSP) will be installed at many intersections in Denver, which will provide longer green lights for buses to progress along Colfax.

Travel Impacts

  • Bus service – 15 and 15L routes will operate during construction. Temporary bus stop closures or relocations are expected. Adjacent stops in the same direction will not be closed at the same time. Stops may reopen between project phases without benches and other amenities. Sign up for RTD rider alerts here.

  • Pedestrian access – Sidewalks near bus stops may be closed during construction. A signed detour route will be provided for temporary sidewalk closures.

  • Lane closures – Parking and lane closures are anticipated during construction. Lane closures are scheduled to avoid peak.

15L Route Improvements Timeline

Preliminary design was completed in first quarter
RTD will finalize the design before construction begins
Construction on the project began in April
Construction will continue through the Spring

Work Hours

  • Denver: Monday - Friday, 7 a.m. to 9 p.m.; Saturday & Sunday, 8 a.m. to 5 p.m.
  • Aurora: Monday - Friday, 7 a.m. to 5 p.m.; Saturday & Sunday, 7 a.m. to 5 p.m.
  • Night work is possible
15L bus shelter rendering Broadway

Rendering of enhanced bus shelter at Colfax and Lincoln

15L bus shelter rendering Lincoln

Rendering of enhanced bus shelter at Colfax and Broadway

15L bus bulb rendering

Rendering of bus bulbs, also known as curb extensions

City of Denver Colfax Corridor Connections

The Future of East Colfax Transit

About The Project

With support from RTD, the City and County of Denver (CCD) is leading the City of Denver Colfax Corridor Connections project which is a study of transit and mobility within the East Colfax Corridor. The stated goal of the project is to improve transit, overall mobility and livability within the corridor now and over the next 25 years. The corridor study area is bounded by I-25 to the west, I-225 to the east, 12th Avenue to the south and 20th Avenue to the north.


An Alternatives Analysis (AA) report was completed in June 2015 with Bus Rapid Transit (BRT) on Colfax being selected as the Locally Preferred Alternative (LPA). Key elements of the BRT are as follows:

  • Exclusive bus-only lane during peak hours for 4.7 miles (Broadway to Syracuse Street)
  • Enhanced bus stops for the entire length of the corridor with bus bulbs/curb extensions where appropriate
  • Branded buses with low-floor, multiple door boarding (off-board fare collection)
  • BRT service would replace the existing Route 15L with more frequent service
  • Exclusive lane will allow right-turning vehicles
  • Exclusive lane will replace a general-purpose travel lane, not the parking lane 

For more information about the City of Denver Colfax Corridor Connections please visit: