At least a dozen times a day, Edward Sparks drives his tractor-trailer along the stretch of beltway where authorities are investigating the shootings of 11 vehicles.

"You're constantly looking," he said.

After the long holiday weekend, commuters were to return Monday to the five-mile stretch of Interstate 270 (search) where the shootings began earlier this year, most in the past two months.

Authorities did not connect the cases until a 62-year-old woman was killed Tuesday while riding in a car driven by a friend; she was the only person hit in the shootings.

Many living and traveling along the stretch of roadway Sunday said they don't intend to avoid the beltway that circles Columbus (search). Often there's no better route.

Traffic hasn't dropped visibly since news of the shootings broke, said Sparks, 53, who makes deliveries between two book manufacturer warehouses. But he has noticed the extra squad cars, which makes him feel safer.

"You don't go through there now that you don't see one sitting in the middle, or driving by," Sparks said.

Many shootings were first reported after Gail Knisley's death on Tuesday. The bullet that killed her came from the same gun as a bullet in one other shooting, but authorities won't say which.

The Franklin County (searchsheriff's office has contacted law enforcement in other cities with similar unsolved shootings to compare the cases, but no matches have been found, Chief Deputy Steve Martin said. He would not say what other shootings investigators have examined.

Increased patrols in the area will continue, Martin said. "We're trying to provide security for people who are down there and have to travel that way to work every day," he said.

Ohio's gun deer-hunting season opens Monday, so the public shouldn't be alarmed at the sight of people with shotguns, Martin said. He asked hunters to be alert to anything suspicious.