The man, who did not want to be named, said he was inches away from being killed when stones and bricks were thrown at his car on the M80 in Glasgow.
Four cars in total were damaged and the drivers left shaken by the attack near Robroyston, described by police as "frankly idiotic".
Three males, believed to be teenagers, stood on the railway line above junction 1 and 2 and threw the bricks and large stones at cars travelling north at around 4pm on Tuesday.
One man, who is in his 40s, told the Evening Times he was terrified by the attack.
He said: "I came to the conclusion that if the stone had hit a couple of inches higher the windscreen would have cracked right in my face and I wouldn't be here now.
"I could have been killed instantly."
He was driving with a passenger from Ardrossan to Glasgow when he spotted large stones being thrown from the railway bridge on to the road.
As he swerved to avoid them, a large stone hit the windscreen wiper and bounced onto the windscreen, cracking it and causing £500 worth of damage.
Anyone with information about the incident should contact Police Scotland on 101.