The Missouri Department of Transportation has started narrowing down potential rural roadway areas where motorists will be allowed to drive 75 mph as the Aug. 28 effective date draws near.

Senate Bill 1408 was passed on May 15, allowing MoDOT to raise speed limits from 70 mph to 75 mph. Gov. Mike Kehoe signed the change into law on July 13.

“We’ve been looking at all of those segments of rural interstate and doing a very objective review to make sure that where (the 75 mph zone) would be is safe to do so,” MoDOT Director Ed Hassinger said.

Hassinger said the agency is looking at all of the individual segments of rural interstate and highways through a criteria-based approach, including elements such as traffic volume, percentage of trucks on the road and whether there is a current crash issue in the area.

“The only one that really I would say we’re not going to look at, at least right now, is I-70 across the state, because most of it is under construction,” Hassinger said. He added that they won’t be looking at metropolitan areas like St. Louis and Kansas City.

“Think places where the road is flat and straight, lower traffic and not as many trucks — those would be the most likely candidates,” Hassinger said.

Hassinger said the department will make a decision in the coming months regarding which roads will see the change. However, that decision doesn’t automatically mean drivers can go 75 mph.

“The speed limit is what the posted sign says at the time,” Hassinger said. “The black and white sign on the highway is the posted speed limit and always is.”

Hassinger said the goal is to have all the decisions made and upgraded speed limit signs put out on the roads by the end of the year.

A fiscal note attached to the law when it passed said MoDOT had determined there are 512 rural interstate and freeway speed limit signs.

“Each location — including materials, installation and labor — is estimated to cost $750 (to replace), for a total of $384,000 if all of the signs are replaced.”