"It is only through sheer luck that nobody was badly injured."
West Yorkshire Police say five vehicles were damaged on the M62 on Tuesday night by rocks and bricks which were thrown at them.
Various reports were received of individuals throwing debris from a nearby bridge and also from the side of the road.
The incidents occurred between 8pm and 10pm at Junction 33 and officers are calling for anyone who saw what happened or have information as to those responsible to come forward.
Sam Grodecki of West Yorkshire Police is investigating the offences and said: “This irresponsible and reckless behaviour could easily have resulted in a life threatening scenario and it is only through sheer luck that nobody was badly injured.
“Their mindless actions on one of the busiest stretches of the regions highways is totally unacceptable and it is important that we trace the individuals responsible.
“I don’t need to spell out what could have happened here, nevertheless, it has left a number of cars and lorries badly damaged and their occupants particularly shook up by their experience.
“Although an extensive search was undertaken along the stretch of motorway, no suspects were located.
“If you were driving from the A1 onto the M62 around Knottingley and saw those involved, we would like to hear from you, particularly if you have in-car recording devices that may have captured their identity.”