SR-154 at Redwood Road; Interchange Design-Build - Salt Lake County, UT

The Utah Department of Transportation (UDOT) selected Wadsworth Brothers Construction Company, Inc. as the design-builder with Wilson & Company as the lead designer to reconfigure the existing intersection at Bangerter Highway (SR-154) and Redwood Road (SR-68) to a full grade-separated Single Point Urban Interchange (SPUI). The key differentiator that resulted in the selection of the project team was the innovative approach to design and construction through the use of a temporary Continuous-Flow Intersection (CFI) as an MOT strategy. This approach reduces traffic volume by 30-35 percent and delay at the intersection by displacing the westbound and eastbound left turn lanes and routing them through the CFI. It also provided improved traffic operations over the current intersection configuration.

When analyzing the existing and future deficiencies of the intersection at Redwood Road and Bangerter Highway, UDOT evaluated several design concepts, including Standard Capacity Improvements, a 2-leg CFI, and a 4-leg CFI. Ultimately, UDOT decided on a SPUI to improve Level of Service (LOS) and signalized intersection delays.

Key elements of the project include:

• Widen Redwood Road to a six-lane urban arterial (three lanes in each direction) with dual left turn lanes southbound and northbound
• Construct a SPUI at the intersection of Bangerter Highway and Redwood Road
• Relocation and replacement of major utilities, including a cell tower, irrigation, South Valley sewer lines, and Rocky Mountain Power poles
• Provide safe bicycle/pedestrian facilities along Redwood Road

As Salt Lake County continuous to grow the SR-154 at Redwood Road Interchange project ties into UDOT’s long-term plan. A plan to ultimately widen Redwood Road from a single-lane urban arterial to a two-lane arterial in each direction with center two-way left turn lanes (TWLTFLs) from 12600 South to Bangerter Highway. In addition, with traffic flows on Bangerter Highway estimated to double by 2040, the improvements on this project are paramount to accommodate long-term traffic and capacity growth projections.