The Utah Department of Transportation is developing plans to improve I-15 through St. George, specifically between Bluff Street and St. George Boulevard. The project aims to accommodate the area's long-term mobility needs by widening the interstate from two lanes to three lanes in both directions.
Construction for this project is expected to begin in mid-2026 and continue through 2028.
As part of the improvements, UDOT plans to widen the northbound and southbound lanes of I-15 between Exit 6 at Bluff Street and Exit 8 at St. George Boulevard. The road will be widened toward the inside to prevent substantial property impacts.
The project also involves raising the interstate as necessary to accommodate additional lanes and minimum clearance heights. This includes replacing bridges and raising I-15 at 100 South and 700 South.
To establish more local connections in St. George, new bridges will be constructed over 400 East and 900 South, allowing for local street connections under the interstate.
Additional work scheduled during the project includes the realignment and installation of several utilities, as well as improvements to drainage along I-15 and local cross streets to reduce flooding. Crews also plan to construct two noise walls on the east side of I-15.
The design phase began in fall 2024 and is expected to be completed in early 2026.
An environmental assessment conducted between 2022 and 2023 evaluated the need for a new interchange at I-15 and 700 South. While the study recommended a single-point urban interchange, UDOT does not expect to build that specific structure at 700 South until a later phase due to fiscal constraints.
