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Greenwood Village News

Posted on: October 4, 2021

Belleview Ave and I-25: Where are we at today?

Birds Eye view of Interstate 25 and Belleview Avenue

Where are we at today?

The Belleview Interchange serves as a major connection in the south Denver region. The interchange experiences heavy traffic throughout the day with high traffic volumes in the morning, noon, and evening peak periods. Nearly 50,000 vehicles per day travel on Belleview Avenue to access places in Greenwood Village, Denver, Cherry Hills Village and unincorporated Arapahoe County. These daily traffic volumes are expected to increase to 65,000 by 2035 due to the region’s growth and development. The existing Belleview and I-25 Interchange is not able to accommodate current and future traffic demands and the addition of future traffic will result in even further congestion and safety concerns.

2012 Corridor Study Launched to Address Traffic Congestion

In 2012, the Belleview Avenue Corridor Plan study was initiated through a partnership between Arapahoe County, City and County of Denver, Greenwood Village and the Southeast Public Improvement Metropolitan District (SPIMD) to help plan for future improvements that would relieve congestion at the interchange and along the corridor. The study area included the area of Belleview Avenue from Monaco Street on the west to DTC Boulevard on the east, including the I-25 Interchange. The plan outlined recommended improvements for automobile, transit, and pedestrian and bicycle traffic along this major arterial.

Several dozen ideas were identified, analyzed, and vetted with each of the stakeholder agencies that participated in the study. The interchange area was fraught with constraints including development on all four quadrants of this already tight interchange; a light rail line along the west side of the interchange; and four closely spaced signalized intersections. The potential solutions resulting from this study established the long-range objective for improving the Belleview Avenue and I-25 Interchange. Stakeholder agencies began collaborating on identifying potential funding sources. A public open house was held on June 19, 2013, to present findings of the study to the public. The Belleview Avenue Corridor Study was later completed in 2016.

Environmental Study Commenced in 2018

As a result of the Belleview Avenue Corridor Study which identified potential solutions to the Belleview Avenue and I-25 Interchange, the next step was for the stakeholder agencies to complete an Environmental Study, required by the Federal Government, in coordination with federal, state and local agencies. The study reevaluated alternatives that were considered in the Belleview Avenue Corridor Study, as well as new alternatives.

The Belleview Avenue and I-25 Interchange Improvement Study began in 2018. The goal of the Environmental Study was to identify a preferred alternative that can move into final design and construction. The technical analysis included alternatives analyzed in a detailed evaluation of specific criteria, including traffic operations, safety, multimodal, community impacts (access, environmental, right-of-way, constructability), and cost.

Two alternatives, along with the No-Action Alternative, made it through detailed screening and were considered for recommendation.

The first alternative is a Single-Point Urban Interchange at Belleview Avenue 
and I-25.
Overhead view of single point urban interchange roadway improvements

The second alternative is a Split Diamond Interchange with Union Avenue and Belleview Avenue.Overhead view of proposed split diamond pattern roadway improvements


In November 2019, the Technical Committee presented their findings to the Project’s Executive Committee. The Executive Committee voted 7-1 to support the Technical Committee’s Split Diamond recommendation as the best alternative. Denver did not support the Split Diamond and requested more time to study the alternatives.

The technical staff completed the requested additional technical analysis in the summer of 2020. The stakeholders also conducted public comment meetings and the public was able to provide input online at greenwoodvillagevoices.com.

After this review, the Technical Committee reaffirmed their recommendation of the Split Diamond alternative. The partners continued discussions on how to move the project forward until in August of 2021, Denver formally announced the split diamond alternative is against their policy and they will not support the option. 

To date, no decision has been made nor agreed upon by the funding partners on the recommended alternative. All funding partners must agree on an alternative to continue the process.

Split Diamond Interchange with Union Avenue and Belleview Avenue; Technical Advantages of the Split Diamond

  • Performs best overall for vehicle traffic operations throughout the interchange as a whole
  • Provides more efficient options for destination distribution of vehicle traffic throughout the interchange area
  • Improves access to adjacent land use destinations in the interchange area
  • Can be constructed without replacement of the I-25 bridge over Belleview and reconstruction of I-25
  • Opportunities to phase construction
  • Belleview and I-25 can remain open and fully operational during construction
  • Includes a new grade-separated pedestrian/bicycle bridge over I-25
  • Includes new multimodal elements on Union Av̮enue

Greenwood Village Position and Recommendation

Greenwood Village supports the Split Diamond Alternative. The Split Diamond provides the best overall congestion mitigation. However, in July of 2021, Denver informed the other project partners that this alternative is against their policy on not adding travel lanes. Denver’s policy on congestion includes the addition of bike, pedestrian, and transit facilities but does not support the addition of vehicle travel lanes. While the Split Diamond includes bike, pedestrian, and transit lanes on Union Avenue it also adds two turn lanes for vehicles. The addition of these lanes on Union Avenue is not consistent with Denver’s policy and therefore, they do not support this alternative.

While we continue to work with our partners, Greenwood Village and Arapahoe County continue to pursue funding so that once agreement is reached on an alternative, the project can be constructed in a timely manner. Congressman Jason Crow has recently included the Belleview/I-25 project on his top project list sent to Congress for consideration in the transportation reauthorization bill to be considered this year.

Next Steps

The next step in the process to make improvements to the Belleview and I-25 Interchange is for Greenwood Village, Arapahoe County, City and County of Denver, and the Southeast Public Improvement Metropolitan District to select one of the alternatives proposed from the study as the “preferred alternative” based on their review of the technical analysis and feedback from the public. This decision is required to apply for construction funding and inclusion onto regional long-term plans. The identified solution, once determined, will proceed through preliminary design including evaluation for environmental impacts, as required by the Federal Government and then a final design can begin. Once funding has been identified and secured, the project will be able to move forward to construction stages, which could be years into the future. It is estimated that split diamond or the single point interchange would cost near $110 million to construct.

For more information, please visit the project page on the Village Voices website.

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