Senate approves allowing rural interstates up to 75 mph; debate cites safety, design and signage costs

The Senate debated and advanced Senate Bill 21 on Jan. 22, a measure that would let the Utah Department of Transportation set higher speed limits—up to 75 mph on rural interstate highways and up to 65 mph on most other highways—based on engineering and safety studies and consultation with local governments.

Sponsor Senator Dimitri(k) said the committee originally drafted a 70 mph cap but amended it in committee to 75 mph; he emphasized that the Department may set lower limits where appropriate and that the amendment permits flexibility rather than mandating 75 everywhere. "They can set it at 70; it just may not exceed 75," he said while answering questions about design speed and safety.

Floor speakers raised multiple concerns. Senator Peterson asked about design‑speed standards and whether some interstates were engineered for 70 mph rather than 75. Senator McAllister and others cited environmental and air‑quality implications, arguing higher speeds could increase emissions; Senator Dimitri(k) and supporters countered that traffic flow and congestion, not higher cruising speeds, are often the larger contributors to pollution. Sen. Howell warned the body to consider potential increases in fatalities tied to higher travel speeds. Practical impacts were also discussed: a fiscal note estimated about $75,000 to replace signs where limits change; trucking representatives said carrier fleets typically set speed governors below posted maxima.

Senators also discussed how local consultation would work and whether the Department would use traffic and safety studies to set limits on specific stretches. The bill’s amendments give UDOT the authority to set a reasonable safe speed and to consult city and county governments where appropriate.

On the roll call recorded in the transcript, SB 21 passed with 26 aye votes and 3 nays and was moved to the bottom of the third‑reading calendar.