Thrown stone smashes windscreen on the A38
A driver's windscreen was shattered when a stone was thrown from a bridge over the A38 in south east Cornwall.
The driver of the Ford Transit van was uninjured as the stone hit the passenger side of the windscreen.
Police said they believe a youth was responsible for the incident which took place on 17 February at 1400 GMT.
Det Sgt Tim Wright, of Devon and Cornwall Police, said: "The risk of serious injury or even death cannot be over-emphasised."
He added: "If the stone had hit the windscreen just two feet closer, then the driver could have been seriously injured, or he could have lost control and crashed his vehicle."