UDOT I-215 Redwood Road DDI Interchange

The Utah Department of Transportation (UDOT) targeted the intersection between Interstate 215 and Redwood Road (SR-68) in North Salt Lake City to improve traffic flow. UDOT wanted to widen Redwood Road and use the existing two-lane bridge over I-215 as part of a diverging diamond interchange (DDI) that would span the highway, among other improvements. UDOT called upon Stanley Consultants for 100 percent design of the $30 million project. The Redwood Road DDI would require an unusual configuration because of local soil conditions. If the new bridge required to complete the DDI were located next to the existing bridge, it would create a drag on the old bridge, which could cause it to sink to the point of failure. The final design reduced the new bridge’s angle that it crosses over the freeway, saving on construction cost because the design shortened the bridge. The intersection won the Engineering News-Record Mountain States 2020 Best Project in the highway and bridge category.