90 Sixth Avenue widening on schedule; pedestrian underpass construction to start next month

Commerce City Public Works briefed the City Council on the 90 Sixth Avenue widening project (Chambers to Tower Road), reporting that the project is progressing and that the separately funded pedestrian underpass will move into construction next month.

Scope and status: Director Jenna Han said the widening includes median construction, two eastbound lanes from Chambers to Tower Road, sidewalks, multi‑use paths, new storm and water lines, traffic signals, a pedestrian underpass and a bridge over Second Creek. Construction began in early 2024; segments east of Tower Road reopened to traffic in September. Paving east of Second Creek began during the meeting week.

Pedestrian underpass: The underpass design — coordinated with Rocky Vista High School — was completed in June and council approved the underpass work order in September. The underpass is planned to be about 155 feet long, 12 feet wide and 10 feet tall, and will include lighting, drainage, retaining walls and a possible public art component. The contractor for the overall widening is also building the underpass; staff said the project remains on track for completion in 2026 and that the school (opening in 2027) will be able to use the facility when it opens.

Public outreach and sound walls: A second quarterly public open house is scheduled for Oct. 1 at South Lawn Elementary; adjacent homeowners will receive mailed invitations and a packet with a prepaid response survey regarding sound walls. Staff said they will return to council with survey results and proposed next steps in late Q4.

Traffic and safety questions: Council members raised specific traffic questions for locations such as Nucla (Nucla/Mobile) and Landmark driveways near Rocky Vista High School, asking whether signals or stop conditions would be added. Staff said the project’s traffic warrants were evaluated and certain side‑street approaches will be right‑in/right‑out or stop‑controlled rather than fully signalized; signal timing will be monitored and adjusted after installation. Staff agreed to post the traffic‑safety study and design plans on the project website and make printed plans available at the Oct. 1 open house.

Why it matters: The widening and underpass are intended to improve pedestrian safety, add multimodal facilities and reduce congestion on a heavily traveled corridor; the underpass is framed as a safety connection for students at the new school.

What’s next: Construction of the underpass is scheduled to begin next month, the Oct. 1 public open house will solicit input on sound walls and staff will bring survey results and recommendations to council in late Q4.