Adelaide motorists feel it's only a matter of time before someone is killed after vehicles were pelted with rocks on the Southern Expressway.
Drivers are being terrorised by the rock throwing, with three attacks in a single day.
Three teenage boys were arrested and charged just days ago for throwing rocks and bottles at cars, but even that hasn't been a deterrent to others.
Early on Monday morning a woman's car was struck by a rock between O'Sullivans Beach and Sherriffs Road.
Another female motorist was targeted north of Honeypot Road half an hour later.
A third victim's front windscreen was smashed by a rock thrown from an overpass.
No-one was hurt, but similar attacks on the Expressway in recent years have left drivers badly shaken and vehicles damaged.
Police and motorists are fearing for the safety of Adelaide road users.
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“Somebody's gonna get killed eventually,” one woman told 7 News.
Another added: “[It’s] not something you want to happen to you, especially when you've got kids in the car."
Chief Inspector Matt Nairn warned throwing objects off the overpass had the force of a "projectile" and could be catastrophic.
"Sometimes you can compare it with firing a gun, it's no different - the potential is there to kill,” he said.
Police want anyone with dash cam footage of the attacks to come forward and urge anyone who notices suspicious activity on the freeway to immediately report it.