The number of fatalities on Iowa’s Interstates has increased in the past year.

The posted speed limit on most miles of four-lane, divided highways in Iowa was raised to 70 miles an hour on July 1st of last year. In the first 12 months under that higher speed limit, there were 48 fatal traffic deaths on the Interstates. In the previous 12-month period, there were 41.

Iowa State Highway Patrol spokesman Jim Saunders says it’s too early to tell whether increase in fatalities had anything to do with the hike in the speed limit. “The 70 mile an hour speed limit is only on selected stretches of rural Interstate and a number of these accidents occured on stretches of Interstate where the speed limit didn’t increase,” Saunders says. “It’s also very feasible that these fatalities could have occured for other reasons such as drivers being intoxicated and people not wearing their seatbelt.”

Saunders says a DOT survey this past spring showed the average speed on Iowa’s Interstate system was 71 miles an hour. That’s roughly equal to the average speed before the legal limit was raised from 65 to 70. “So people are staying pretty well within the limit of 70 miles an hour,” Saunders says.