COLUMBUS -- Ohio would make it illegal to stay in a highway's left lane if not passing or exiting, under a bill that previously drew attention for another provision that would raise the speed limit on the state's interstates.

Left-lane restrictions could make Ohio roads safer, this bill's sponsor said.

"If someone's in the left-hand lane and someone's trying to pass them on the right . that is dangerous," said Republican state Rep. Ron Maag of Lebanon, in southwest Ohio.

His measure would bar drivers from traveling in the left lane of a highway except when getting by a slower vehicle, using an exit on the left, allowing other motorists to enter the right lane, or when snow or other road conditions would make it unsafe to use the right lane.

Ohio troopers questioned how the proposed left-lane limitations would work and be enforced.

"We believe both lanes are needed to maintain the traffic flow with the amount of traffic on a four-lane, divided interstate," said Lt. Anne Ralston, a spokesman for the Ohio State Highway Patrol.

The patrol wondered how troopers would be able to tell if, for example, someone in the fast lane was trying to get ahead of another vehicle or simply was taking advantage of unoccupied pavement.

Mr. Maag responded, "I don't know of any law that is easy [to enforce]. There are laws against bank robbing, and people still rob banks."

The law currently in effect in Ohio requires drivers to use the right or center lanes, but there are a number of exceptions.

John Bowman, a spokesman for the National Motorists Association, said a stricter left-lane law could be beneficial if motorists are educated about why it's important to keep slower drivers from clogging the left sides of highways and backing up traffic.

"Other cars have to slow down suddenly or speed up suddenly or make sudden changes back and forth. You're introducing uncertainty and unpredictability into traffic flow," said Mr. Bowman.

Mr. Maag's measure also would raise the speed limit on Ohio's interstate highways to 70 mph from 65.

First Published February 1, 2012, 5:10 a.m.