GRINNELL, IOWA ? A new study shows that most Iowa motorists zoomed past the speed limit on the state’s four-lane roadways in a recent three-month period, and the results have one lawmaker talking about raising the limit.

Eighty-nine percent of motorists on Iowa’s four-lane freeways and expressways violated the 65-mph speed limit during the study, which ended Sept. 30. That’s a 20 percent increase from the same period in 1995, according to Iowa Department of Transportation records. The statistics were collected from selected highways.

“Iowans obviously want a higher speed limit. It is only the Iowa Legislature and the governor that haven’t figured that out yet,” Rep. Christopher Rants, R-Sioux City, told The Des Moines Sunday Register in a copyright story.

Rants, the next House speaker, said he planned to ensure that proposals to raise Iowa’s speed limit to 70 or 75 mph receive a fair hearing during the upcoming legislative session.

Highway safety advocates have fought increasing Iowa’s speed limits, citing studies that show faster speeds increase the likelihood and severity of vehicle crashes.

Allan Williams, chief scientist for the Virginia-based Insurance Institute for Highway Safety, said raising the limit tends to increase drivers’ speeds.

“People are looking at what the police tolerance level is,” Williams said. “The consequence of this extra mobility is more fatalities.”

In Nebraska, where the average speed on rural interstate highways has increased to 78 mph, a record 50 people have been killed in rural interstate crashes this year. The speed limit was raised from 65 to 75 mph on rural interstate highways in 1996.

Fred Zwonechek, administrator of the Nebraska Office of Highway Safety in Lincoln, said a wider disparity in rural interstate speeds creates more hazardous driving conditions.

“We have those crazy people who want to drive at 90 and feel comfortable, and we have people driving 55 and 60 who never felt comfortable at 65,” Zwonechek said.

Iowa and Oregon are the two states west of the Mississippi River in the continental United States with maximum 65-mph posted speeds. Motorists can drive at least 70 or 75 mph in the other Western states.

Increasing the speeds in some of those states has had an effect.

Traffic deaths on rural interstate highways increased in four states next to Iowa where legal speeds were raised to 70 or 75 mph, according to a report earlier this year by an Iowa task force on speed limits.

Nebraska was the worst. A comparison of average annual fatalities from 1993 to 1995 and from 1996 to 2001 show a 58 percent increase in rural interstate deaths.

The other states were Missouri, South Dakota and Minnesota.

In Kansas, which has a road system and population similar to Iowa’s, traffic deaths skyrocketed after speeds were raised to 70 mph on interstate highways and 65 mph on primary highways in 1996, according to Iowa DOT research.

Eric Skrum, spokesman for the Wisconsin-based National Motorists Assn., contends some highway-safety advocates are selective in the statistics they use.

Considering Americans’ increased use of automobiles, highway fatality rates have dropped nationwide since Congress voted in 1995 to permit each state to set its own speed limits, he said.