The speed limit on U.S. Highway 20 between Idaho Falls and Ashton will increase from 65 to 70 mph Wednesday.
The new speed limit will affect both passenger vehicle traffic and commercial trucks and stems from engineering and traffic studies which indicated that 85 percent of drivers travel the route at 70 mph or below, according to an Idaho Transportation Department news release.
Setting speed limits to the 85th percentile speed results in the lowest crash rates, according to the news release.
“Raising the speed limit to 70 mph will further traffic safety and mobility,” District 6 Traffic Engineer Ben Burke said in the release. “Posted speed limits can’t replace common sense, however. Drivers should always slow down if necessary to meet hazardous conditions.”
Idaho Transportation Department officials discussed the proposed speed limit increases with county officials and law enforcement prior to formalizing the changes.
Speed limits also will be adjusted in transition areas on each side of the affected route on U.S. 20. The speed limit between Lindsay Boulevard and Riverside Drive will be lowered from 55 to 45 mph.
The 65-mph speed limit will remain in effect until the new 70-mph signs are posted, the release said.