A rock has been thrown through a car windscreen on the A120 in Essex.
Officers from Essex Police have described the incident as "extremely dangerous" and are appealing for witnesses.
The woman driver of the car was unhurt.
The incident happened on Wednesday night (September 19) on the A120 near the turn-off to Great Bentley, the B1035.
The driver saw a youth or man standing on the near side of the A120 as she headed towards Colchester. He was wearing a dark top with jeans and trainers.
The woman was driving a red Seat car.
Anyone with information about this incident is asked to contact Pc Carly Stokes or her colleagues at Colchester Police on 101, or Crimestoppers on 0800 555 111.