UDOT identifies Center Street as preferred site for I‑15 Spanish Fork interchange; public comment open through Jan. 3

The Utah Department of Transportation on Thursday told the Utah County Commission it has selected a Center Street interchange as the preferred alternative in its I‑15 Spanish Fork environmental assessment, estimating the project would cost about $180,000,000 and reduce vehicle backups dramatically compared with a do‑nothing scenario.

Darren Bunker, UDOT project manager, said the study screened five initial alternatives and advanced one option for full evaluation. "When it came down to it, out of all those options, we settled in on the preferred alternative, which was a interchange at Center Street," he said, adding the design includes moving railroad tracks west to accommodate a future light‑rail station and a multi‑use trail to improve pedestrian and bicycle access.

UDOT told the commission the project yields significant regional mobility benefits: by 2050 the Center Street interchange would reduce anticipated backups at the Benjamin interchange from roughly a half‑mile to about a tenth of a mile and cut Main Street backups from nearly 2.5 miles under the do‑nothing scenario to about two‑tenths of a mile. Bunker cautioned the interchange is not a "silver bullet," noting it funnels additional traffic onto Center Street and that some intersections will still experience congestion.

On environmental impacts, UDOT said the work would affect approximately one‑third of an acre of wetlands, three historic properties with "de minimis" Section 4(f) impacts, seven full acquisitions and 32 partially impacted parcels, and — importantly — would not require relocating residents. The agency also flagged noise impacts near Center Street and along I‑15 and said noise mitigation decisions would be made at the design stage.

UDOT staff said the agency assumed another nearby interchange project in regional plans and that the final layout could be affected by a separate environmental study for a new light‑rail station. The department will publish its environmental assessment and is accepting public comment for 30 days; Bunker said comments are due by Jan. 3 and the team expects to publish a formal EA resolution around March.

Next steps: UDOT will hold public meetings (in‑person and virtual) to gather input during the comment period and will compile and respond to comments before advancing the project in the environmental process.