A southwest view of the Dixie Drive interchange, with the Bluff Street Interchange to the north.
Construction of the new I-15 Dixie Drive Interchange in St. George, Utah, is nearing completion. The Utah Department of Transportation (UDOT) secured state funding and began design for the project in the spring of 2009. Construction commenced in fall of 2009.
The new interchange was formed by realigning Dixie Drive along the north side of the Southgate Golf Course and connecting to I-15 at the south end of the Dixie Center. It is now connected to the Bluff Street Interchange through a system of one-way collector/distributor roads.
Washington County Constructors (WCC) — a joint venture of Utah-based Ralph L. Wadsworth & Granite Construction — served as the prime contractor on the job. WCC was involved in the design phases as part of the CMGC (Construction Management/General Contractor) process.
The project team has received two accolades for its leading-edge design and construction of the interchange. First was a recognition by the Associated General Contractors of Utah. Second, UDOT and Washington County Constructors were awarded the 2012 Excellence in Concrete Award from the American Concrete Institute.
WCC constructed six bridges, the Hilton drive box culvert, the pedestrian tunnel and a 3000-LF sheet pile wall along with all roadway work, including excavation, earthwork and paving.
WCC subcontracted Western Rock to supply the concrete and Gerber Construction for MSE walls. Hansen Eagle Precast provided the girders and Hayward Baker supplied stone columns. Golf course excavating, sewer and storm drain work was performed by JP Excavating.
Other subcontractors include Restruction Corp. for polymer overlays, Intermountain Slurry Seal for micro-surfacing, and Most Wanted Drilling, for drilled shafts.
The project affected a few holes of an adjacent golf course. City planners took advantage of this to reconfigure and expand the course in conjunction with project mitigation efforts.
These efforts include a host of trail work. Crews are reconstructing the Confluence Trailhead, and realigning/reconstructing portions of the Virgin River Trail and the Hilton Drive Trail. The bridge connecting the Virgin River trail to the Webb Hill Trail also is open.
The completed interchange will provide a more direct east-west corridor for the southern portion of the city. Local street improvements are being conducted to take advantage of the new connection. The project is on schedule with landscaping expected to be completed by the end of July.
The city of St. George is among the early pioneer settlements pre-dating Utah statehood. Crews were surprised when they unearthed pre-historic artifacts on a hill adjacent to the project. This booming area is now Southern Utah’s largest city and the Dixie Drive Interchange is built in one of the fastest growing metropolitan areas in the nation.
The project was delayed when widespread flooding from heavy winter storms pushed the Santa Clara and Virgin Rivers beyond flood stage. The flood affected several areas in Washington County. The project lies at the confluence of these rivers. A few weeks were lost to removal of sediment, local utility repairs and drying out the project area along with appropriate permitting and funding for the disaster.
The “usual suspects” in machinery were used for the job, including three excavators, two 950 loaders, a Cat615 paddle wheel, two grade rollers, two water trucks, a 250-ton hydro crane, a 120-ton lattice crane, and several man lifts/forklifts. Granite cut 120,000 cu. yds. (91,800 cu m) of excavation and used it on the job. It used 70,000 tons (63,490 t) of hot mix asphalt for paving.
According to UDOT, “this much needed project will dramatically improve the travel from Dixie Drive to I-15 and will also provide great benefits to the Dixie Convention Center in terms of accessibility and convenience. With the fast-growth predicted for the St. George, this project is also designed to relieve the congestion at the Bluff Street interchange as well as the Bloomington interchange.”