House passes bill allowing UDOT to reexamine interstate speed limits after engineering review

The Utah House on Feb. 6 passed House Bill 80, which directs the Utah Department of Transportation to review posted speed limits on interstates and other limited-access highways and to permit increases where engineering studies, crash data and prevailing speeds support a change.

Representative Jon Dunnegan, sponsor of the bill, said the measure continues five years of pilot work and formalizes a methodical review process. "Once the vehicles are at speed ... there is little change in emissions when operating at vehicle speeds between 55 and 75," Dunnegan said, summarizing an air-quality review he distributed to members. He told colleagues the initial test sections showed prevailing speeds rose only one to two miles per hour after changing the posted limit and that UDOT examines engineering, crash history and prevailing speed before recommending changes.

Members pressed the sponsor on safety and enforcement. Representative Briscoe asked whether the air-quality data — which included a University of California study and local Wasatch Front figures — reliably reflects Utah conditions; Dunnegan pointed members to county-specific analyses and said diesel particulate measurements decreased at higher speeds in some data he cited. Representative Chavez Houck sought clarification about earlier news coverage that she said suggested "no fatalities" in 80-mph zones; Dunnegan replied his point was narrower: there were no speed-related fatalities attributable to the increase from 75 to 80 in the pilot sections.

Several members raised enforcement and behavior questions. Representative Rhett asked whether enforcement margins change at higher limits; Dunnegan said the Highway Patrol sets enforcement practices and typically affords less margin at higher posted speeds. Dunnegan also highlighted seat-belt usage as a major determinant of survivability in crashes, saying higher restraint rates could have saved lives in previous years.

Opponents warned of "speed creep" and urged close monitoring if limits rise in more populated corridors. Representative Ipsen supported the measure but noted that Highway Patrol officers testified enforcement would continue as before: "If the speed limit is 65 and you go faster than that, you're gonna get a ticket," he said recounting the patrol's policy in committee.

After extended questioning and debate, the House approved HB 80 by a recorded vote of 63 yes to 8 no. The bill will be transmitted to the Senate for its consideration. The sponsor said any changes would follow UDOT engineering studies, crash-data review and local analyses before altering posted limits.

The House recorded the bill's final vote on the floor and then moved on to other business.