A motorhome has been hit with a brick which was thrown at it while driving along the A467 Risca bypass in South Wales on Sunday evening.
Daniel Aldridge said thousands of pounds worth of damage had been caused.
The 32-year-old had been travelling home to Bargoed from Switzerland with his partner and two young children, aged one and six, when the incident happened.
He said their vehicle ended up swerving sideways into the road following the impact which he said felt “just like a crash”.
A spokesman for Gwent Police said: “We received reports of criminal damage on the A467, Risca, on the evening of Monday 8 January whereby vehicles have reportedly been damaged by bricks, reportedly thrown from the roadside. Officers attended and enquiries are ongoing.”
Speaking to WalesOnline, Daniel said: “We were on our way home from Switzerland in our motorhome when someone threw a breeze block from the side of the dual carriageway at us. It hit the side panel of our windscreen.
“It smashed the windscreen and cracked the [side panel]. It’s a good job it didn’t come through the windscreen as it could have killed us.
“When it happened I had to brake sharply and we skidded around sideways into the road. It felt exactly like a crash and I don’t know how we didn’t end up on the roof.
“We had driven three thousand miles without an issue after spending Christmas in Switzerland, then 20 minutes from home this happened.
“I haven’t slept in two nights and I feel sick as a pig.
“My children feel too scared to go in the motorhome now.”
It is one of several reports of similar incidents along the stretch since October.