Eagle-Vail Half Diamond Interchange
Vail, Colorado

JFSA conducted an environmental analysis on the Eagle Vail ½ Diamond project site and successfully obtained a categorical exclusion allowing the design team to progress from preliminary design to final design. The Eagle Vail ½ Diamond is located where US 6 crosses under I-70 at milepost 169 approximately 2 miles West of the Dowd interchange. The significance of this project is related to the fact that the Dowd interchange is one of the worst accident locations on the I-70 corridor. By adding another connection to I-70, the traffic volume on the Dowd Interchange and US 6 West was reduced and consequently, the accident rate was reduced. JFSA faced the challenge of designing a half diamond interchange in challenging terrain without purchasing any additional right-of-way in a location where there was very little right-of-way to begin with. The design team was able to fine-tune the alignments and profiles providing the most economical solution with respect to the CDOT project criteria. Multiple design iterations were performed to minimize wall heights and maximize traffic operations. US 6 under I-70 was widened from a two-lane highway to a three-lane highway with a left turn bay. In order to get the necessary additional width on US 6 without widening or changing the existing structure, JFSA widened into the existing slope paving under the I-70 structures and tied the soil back with soil nail walls. Even with the tight right-of-way constraints, JFSA was able to design a sediment pond capable of handling the 100 year flood volumes, but more importantly provide cleaner storm water out-letting into the pristine Eagle River. Extensive coordination efforts with the utility agencies and partnering with the Eagle River Water and Sanitation District to provide a new 24" sewer main line minimized utility conflicts during construction. JFSA also provided construction services, ensuring a seamless transition from design to construction.

The JFSA team also provided services in the areas of survey, noise studies, lighting design, geotechnical engineering, and landscape/aesthetics.

Reference: CDOT Region 3, Keith Powers, 970.328.6385