Speed limits on interstates across southern and eastern Idaho increased Thursday.
Idaho Transportation Department workers posted the increase to 80 mph for vehicle traffic and 70 mph for trucks in a single day.
The Idaho Transportation Board allowed the increase at its July 11th meeting after agreeing to recommendations from staff, despite concerns from the public. There is a requirement of an annual review by the board to ensure safety.
"Obviously there are greater risks at higher speeds. You get up to 60 miles per hour, that's fast, and anything beyond that is faster. Therefore we have to all be concerned about those. But in the studies that we conducted we discovered that it would serve safety and mobility goals," said public relations officer for the Eastern Idaho Department of Transportation, Bruce King.
Interstates 15, 84, and 86 will be increased, except for urban stretches in Idaho Falls, Pocatello and the Treasure Valley between Caldwell and Boise. Those areas will remain at 65 mph.
Idaho State Police want to remind drivers that the speed limits come with greater risks, so they will be enforcing no tolerance for drivers speeding in these areas.
"80 miles and hour really means 80 miles and hour," said Idaho State Police Lt. Chris Weadick. "Some of our concerns with the new speed limit is feet per second that the vehicles are now traveling. Their traveling distance is a bit faster, and the closing distance between the travelers in front of them can be greatly increased."
Drivers traveling at 75 miles per hour travel 110 feet per second with 433 feet in total stopping distance. Those traveling at 80 miles per hour travel at 117.3 feet per second with 481 feet or 1.5 football fields, in total stopping distance.
According to ITD, there will be no changes to Interstate 90 through northern Idaho. The department is studying activity on several state highways. Changes could come to many of those areas, starting with Highway 20.