Police patrols are to be stepped up in New Scotland Road, Nelson, after the passenger window of a car was shattered by a stone on Sunday afternoon.
The car was being driven along the road in the direction of Barrowford when the stone was thrown at it from the kerb.
The female front seat passenger, who has asked not to be named, was lucky not to be seriously injured and was just showered with glass.
But back seat passenger David Garnett said: “She was very lucky. Had she not been talking to the driver, I shudder to think what may have happened.”
There have been reports in recent weeks of eggs being thrown at passing vehicles in the area, but this is believed to be the first involving a stone being thrown.