Most of the shootings occurred in the past two months. The only person hit was a 62-year-old woman shot to death Tuesday while riding in a car driven by a friend.
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, including another truck driven by a friend.
"You're constantly looking," he said.
Many living and traveling along the stretch said they are not avoiding the beltway. 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.
"(Monday) morning, I'm right back on the road. I'm not ducking or anything."
Terry Daugherty, of Pikeville, Ky., had to pass through the stretch of highway Monday on his way home from visiting family for Thanksgiving. The shootings were a topic of discussion on the holiday, and relatives told him to be careful during his drive.
"Life goes on. You've still got to live, travel and visit," he said while buying coffee and candy at a gas station. "You don't want to go through the heart of the city. You can't shut down the freeway for a couple of shootings."
Authorities did not realize the shootings were happening on the same stretch until Gail Knisley's death last Tuesday; many shootings were first reported afterward. 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 sheriff'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.
One or more people are deliberately targeting drivers, but Martin refuses to use the word "sniper." Authorities are keeping open a tip line and have set up a post office box in Columbus, inviting the shooter to call or write.
Shooting at a moving vehicle on a freeway could be a game to the person holding the gun, an expert told the Columbus Dispatch.
"Because the victim is inside a car, it can be psychologically easier for the shooter," said James Alan Fox, a professor of criminal justice at Northeastern University in Boston and a former FBI official. "In their mind, they're shooting at inanimate objects. It's more like target practice or a video game."
He compared freeway shooters to those who drop rocks and other objects from overpasses onto moving vehicles.
"The fact that someone is inside the car certainly raises the stakes," he said. "It adds to the excitement and the risk."
However, "if this started as someone looking for thrills, things have changed. This is murder."