Alternatives Evaluation
Completed in 2013, the I-70 Kipling Interchange PEL Study carried forward four interchange configuration alternatives and a No Action alternative for potential investigation in the next phase of study. It also recommended two of those configurations (Single Point Urban Interchange and Traditional Diamond Interchange) for consideration as the preferred alternative in NEPA documentation because they met the purpose and need to the highest degree while minimizing environmental and community impacts.
In late 2016, CDOT moved the project forward into the National Environmental Policy Act (NEPA) and Preliminary Design phase. This phase is expected to last almost 18 months. The first step of this phase involves determining the preferred alternative. To do this, CDOT and agency stakeholders reviewed information gathered during the PEL Study, and also considered any new conditions and information that became available since it was completed.
During early agency scoping before the NEPA phase of the project, another interchange alternative—the Diverging Diamond Interchange (DDI)—was recommended for consideration as the preferred alternative. The DDI alternative was analyzed in the PEL Study and was not recommended for further consideration at that time because it did not meet the purpose and need as well as the other alternatives.
However, with recent design advancements and multimodal benefits achieved with construction of the interchange configuration at other locations in Colorado, the DDI alternative was re-evaluated in comparison to the Single Point Urban Interchange and Traditional Diamond Interchange alternatives. The DDI is the preferred alternative because analysis shows it will provide substantial safety benefits for all modes of travel and improved vehicular operations.
