Adams County and Brighton advance multimodal vision for 120th Avenue; preferred design favors raised multiuse paths and transit lanes

Adams County, Brighton and partner agencies presented a multimodal corridor study for 120th Avenue on Feb. 11 that recommends a multimodal design combining transit lanes, separated bike facilities and wider shared-use paths as the preferred alternative.

Jennifer (senior transportation planner with Michael Baker International) presented crash and travel data and said the team reviewed five years of crashes (2017–2021) and identified three fatal crashes on the corridor during that period. The study team identified US‑85 and Sable Boulevard as Tier 1 crash hotspots, and Chambers and Buckley as Tier 2 locations.

The study area runs from U.S. 85 to Tower Road and crosses three jurisdictions: Brighton, Commerce City and Adams County. The consultants tested three alternatives and evaluated them against travel time, multimodal safety, right-of-way impact, environmental factors and funding competitiveness. The preferred alternative (the team’s top-rated option) includes: - a bus-only lane that could, in some locations, serve as a right-turn lane and that staff said could be shared with school buses; - raised or separated on-street bike facilities combined with 8–10 foot shared-use paths on both sides of the corridor (the team recommended a 10-foot minimum for multiuse paths); - positive left-turn offsets, redesigned channelized turns and targeted raised intersections near schools to slow vehicular traffic and improve visibility for pedestrians and bicyclists.

The team told council that public outreach showed strong interest in multimodal improvements: a Metroquest survey attracted more than 300 participants and about 9,000 mapped data points; open houses drew roughly 80–200 attendees. Public responses favored Alternative 2 in the online poll, while the technical advisory committee and the consultant scoring ranked Alternative 3 highest; the final recommended design incorporates the committee’s and public’s preference for raised bicycle facilities and wider shared-use paths.

Jennifer said the preferred design also responds to major planned development along the corridor, which the consultants said will substantially increase future traffic volumes. She highlighted school-area safety work: a proposed signal at Salem by Prairie View High School, possible raised intersections at the middle- and high-school crossings, and coordination with schools on parking reconfiguration to improve turning movements.

Council members raised implementation questions. Several asked about coordination with Commerce City and the status of the US‑85/120th interchange: the interchange design (led by Commerce City, with CDOT and Union Pacific as stakeholders) is at roughly 30% and Commerce City has been pursuing CRISI (Consolidated Rail Infrastructure and Safety Improvement) funding to progress design of grade separations. Consultants and Adams County staff emphasized the need to place the corridor project on regional programming lists (DRCOG TIP, CDOT plans) and to pursue competitive grants; the team said it has applied for RAISE/build grants and an HSIP application for the Salem signal.

Public-safety engineering details presented include positive left-turn offsets (to improve sight distance at permissive lefts) and redesigned channelized right-turn geometry to reduce vehicle speeds and increase visibility for pedestrians and bicyclists.

Next steps: the study team will hold a public open house March 11 to show the full concept design; final project materials and a report are slated for May. Staff said they are pursuing grant applications to move design and construction forward, and that the corridor’s implementation will require interagency agreements and significant funding.