A rock hit a car’s windscreen after being thrown off a bridge over the A14 at Kettering.
The incident took place between 1pm and 2pm on Wednesday (January 23) at the bridge near Junction 9.
Police said an ‘unknown’ male threw a rock from the bridge onto the busy dual carriageway, hitting the victim’s car.
The windscreen was left with a small hole.
A police spokesman said: “Throwing items off bridges into traffic is extremely dangerous and can cause serious injury and in some cases, death. “Anyone found to be doing so will be dealt with robustly by Northamptonshire Police.
“Anyone who witnessed this incident should contact us on 101 or via Crimestoppers anonymously on 0800 555111.”
In 2007 HGV driver Laurence McCourt was killed after a breezeblock was thrown off a bridge on the A45 between Wellingborough and Great Doddington.
Two 15-year-olds were locked up for their part in his death.