St. George • State officials and St. George residents gathered at Dixie Middle School Wednesday to preview a $195 million project aimed at widening Interstate 15 and bridging the gap dividing the city.
St. George, as city leaders often note, has significant barriers to efficient transportation. It is surrounded by ridges on three sides — on the north, east and west — and the interstate cuts through the center of town and separates residents living on either side of the highway.
While St. George’s geographical barriers cover too much ground and would cost too much to change, according to highway planners, the I-15 widening project will improve traffic flows and connect neighborhoods now separated by the freeway.
As currently designed, the project would widen north and southbound I-15 from two to three lanes along the 2.5 mile stretch from Bluff Street to St. George Boulevard.
It would also replace highway overpasses at 100 South and 700 South with two taller bridges that are wide enough for three lanes in each direction. Noticeably absent is a 700 South interchange that was included in an earlier plan but has been delayed due to a lack of funds.
The new plan proposes raising the highway’s height to accommodate two new underpasses that will connect neighborhoods now separated by the interstate, one on 400 East (Flood Street) and another at 900 South. Currently, the only roads that cross I-15 are located at St. George Boulevard, 100 South, 700 South and Bluff Street, which are often clogged during peak travel hours.
“The two underpasses will greatly improve commutes for many residents in St. George,” city spokesperson David Cordero said. “The impact is especially significant for those walking or riding a bike, reducing some travel times by half. This provides better access to downtown, several schools, parks and other community amenities.”
Congestion versus safety
(Google Maps; The Salt Lake Tribune) A U.S. Department of Transportation grant will help fund the construction of two underpasses in St. George aimed at connecting neighborhoods now separated by Interstate 15. The new underpasses will be built at 400 East (Flood Street) and at 900 South.
Specifically, city and transportation officials say the two new underpasses will reduce congestion and improve access to Dixie High School and Dixie Middle School, the boundaries for which currently straddle both sides of the interstate. The new crossings would enable students living in the neighborhood just west of the interstate to walk to either school on the opposite side in five minutes instead of having to go as much as a mile out of their way to cross the freeway at Bluff Street or 700 South.
For St. George resident Walt Brooks, who used to walk under a 3-foot culvert to cross the highway en route to school as a boy, the underpasses are long overdue.
“The underpasses will be a major and much-needed improvement,” he predicted.
Nancy Norbeck, who was also at the hearing, vehemently disagrees, saying the underpasses will put more traffic on 900 South, much of which will end up on 400 East and endanger students crossing the road on the way to and from school.
“Unless they put a light or a four-way stop there, no one will be able to safely cross that street,” she said.
Myron Lee, transportation planning director for the Dixie Metropolitan Planning Organization, said students, as always, will have to look both ways before crossing the street. That said, he contends the two underpasses will help the community stitch itself back together.
(Mark Eddington | The Salt Lake Tribune) St. George residents examine the preliminary design of the Utah Department of Transportation $195 million improvement project at Dixie Middle School. on Wednesday, June 25, 2025.
“It will also help reduce the congestion we now have on 700 South because the traffic will no longer be channeled to that one underpass,” he said.
Funds for the underpasses are coming from an $87.6 million grant the city and state received in 2024 from the federal Reconnecting Communities and Neighborhood program, which was established as part of the Bipartisan Infrastructure Law passed during the Biden administration. The remainder of the I-15 widening project will be paid for with transportation investment funds, according to Brett Anderson, project manager with the Utah Department of Transportation.
Since the underpasses were not part of the original plan and added after the environmental assessment for the project was completed, UDOT officials had to “re-evaluate” the assessment to incorporate the additional improvements. Anderson and other officials were on hand to discuss the noise issues and several other environmental impacts detailed in the draft reanalysis.
Over the next two months, UDOT will send ballots to people living closest to I-15 to let them vote on whether or not they want sound walls to protect them from additional traffic noise. Federal regulations require 75% of those ballots to be filled out and returned, and 75% of respondents must vote in favor before sound walls can be built.
According to Lee, roughly 60,000 vehicles per day travel I-15 between the Bluff Street and St. George Boulevard exits, which the transportation director said is projected to increase to 94,500 vehicles by 2050. Construction on the I-15 widening project is expected to begin by mid-2026 and wrap up in late 2028.
UDOT officials are accepting public comment on the widening plan and draft re-evaluation until July 7. Click here for more information about providing feedback.