The EA evaluation was completed in September 2012, and resulted in a recommendation of the Improved Partial Cloverleaf Alternative.
Alternatives Evaluation Process
A tiered alternatives development and screening process was used to evaluate alternative elements moving forward into this NEPA process. See the Project Background page for more information.
This NEPA study included documentation of previously considered alternatives, re-evaluation of the reasonable alternatives from the Arapahoe Road Corridor Study and System Level Feasibility Study, and evaluation of newly suggested reasonable alternatives. Evaluation was based on the purpose and need for improvements and project objectives, and included investigation of traffic, community and environmental impacts.
Following the project’s first public meeting held in April 2010, the project team received a tremendous amount of comments and roadway improvement suggestions from community members and local agency representatives. In keeping with the requirements of NEPA, all reasonably feasible alternatives for the I-25/Arapahoe Road interchange were investigated.
Below is a list of alternatives evaluated in the EA project. More information describing these alternatives and related alternatives evaluation results was provided at the September 8, 2011 public meeting.
The graphic to the right illustrates the three level alternatives screening process (click to enlarge). At the conclusion of the Level 2 screening process in July 2011, the project consultant recommended one "action" alternative, the Improved Partial Cloverleaf without Costilla Crossing, and a "No action" alternative be moved into further detailed, Level 3 analysis and comparison in the Environmental Assessment report. See the July 2011 news release and the August 2011 news release for more information.
Interchange Alternatives Reconsidered from the Arapahoe Road Corridor Study and System Level Feasibility Study
- Tight Urban Diamond
- Directional Ramps
- Diverging Diamond
- Three Level Diamond
Suggested Alternative Locations for Supplemental Crossings of I-25
- Peakview Crossing
- Caley Crossing
- Connection to Clinton Court
- Connection to Costilla
- Costilla to Briarwood
- Costilla to Alton Way
- South of Costilla to Alton Way
- North of Easter to Alton Way:
- Easter to Alton Way
- North of Easter Lane to Alton Way
- Easter Lane to Alton Way
- Geddes to Alton Way
Arapahoe Crossing Alternatives
- Three Level Construction Without Replacing Existing I-25 Bridge
- Through Traffic in Covered Lower Level
- Through Traffic in Open, Trenched Lower Level
- Separated, Trenched Through Lanes on Outside and Local/Ramp Traffic on Middle Level
Interchange Design Options
- No Action
- Improved Partial Cloverleaf without Costilla Crossing
- Improved Partial Cloverleaf with Costilla Crossing
- Single Point Urban Interchange With Single Ramp-Metered On-Ramp
- Single Point Urban Interchange With 2 Lane Collector/Distributor Road from Arapahoe to Orchard
- Single Point Urban Interchange With Eastbound to Northbound Loop Ramp
Other Arterial Street, Intersection and Operational Improvements Suggested by Public
- From Arapahoe LRT Station to Caley Avenue, to Boston/Clinton Street to Costilla Avenue
- From Arapahoe LRT Station to Caley Avenue, to Boston Street, to Peakview Avenue, to Havana and Arapahoe Road
- From Orchard Road to Havana Street to Arapahoe Road
- Various Potential Arterial Improvements such as Auxiliary Lanes on Arapahoe and Approach Roads, Signal Coordination and Timing, Add Pedestrian Grade Separations
- Personal Rapid Transit System Around Interchange Complex