Project Overview 

UDOT is designing improvements for I-15 through St. George to accommodate the area's long-term transportation and mobility needs. These improvements will widen I-15 to three lanes, replace multiple bridges, and construct new bridges to establish more local connections in St. George. 

This project is currently in the design phase and is expected to begin construction in Fall 2026 and last through late 2028. 

During the project crews will:  

  1. Widen northbound and southbound I-15 from two lanes to three lanes between Bluff Street (Exit 6) and St. George Boulevard (Exit 8) 
  2. The road will be widened to the inside to avoid substantial property impacts. 
  3. Replace bridges and raise I-15 at 100 South and 700 South to accommodate the additional lanes and minimum clearance height. 
  4. Construct new bridges over 400 East and 900 South to establish local street connections under I-15.   
  5. Coordinate the realignment of several utilities and the installation of new utilities. 
  6. Improve drainage along I-15 and local cross streets to reduce flooding.  
  7. Construct two noise walls on the east side of I-15.  

Key Features Map:

 An illustration of the project area and planned improvements for the project. UDOT PIN 18218 

To find information about the improvements happening on Bluff Street, visit their project website.  

live
live

Design 2024 - 2026

UDOT is developing final design plans for improvements to I-15 including:

  • Building an additional lane in each direction on I-15 between Bluff Street (Exit 6) and St. George Blvd (Exit 8)

  • Raising I-15 and replace structures at 100 S and 700 S

  • Raising I-15 and build new structures over 400 E and 900 S

  • Building new local roads to connect 400 E 900 S under I-15

Design began in fall 2024 and is expected to be completed in early 2026.

planned
planned

Construction 2026 - 2028

Construction is expected to begin in mid-2026 and continue through 2028.

complete
complete

Environmental Assessment 2022 - 2023

UDOT prepared an EA to determine the need for a new interchange on I-15 and 700 South, evaluate interchange alternatives, and identify environmental impacts. This EA started in April 2022 and was completed in October 2023.

UDOT is not expected to build the study's recommended single-point urban interchange (SPUI) at 700 South until a later phase due to fiscal constraints.

Contact Information

To contact the public information team with questions or concerns:

Hotline | (435) 280-2266

Email | i15stgeorge@utah.gov