New research finds more than 1,000 motorists - more than two a day - were hit by "motorway missiles", such as bricks thrown from bridges, in 2012.
It's hard to understand the mindset of the sort of person who would stand on a bridge and deliberately throw missiles at vehicles on the road below.
But sadly it's something that does take place.
What's more, it is on the increase, according to recent research by windscreen repair and replace firm Autoglass.
Thirteen police forces across the country replied to Autoglass' Freedom of Information request on missile throwing incidents.
1,021 'motorway missile' attacks in 2012
The results show that there were 1,021 attacks during 2012 – more than two a day.
This is a jump from similar research carried out by Autoglass in 2011 where 10 police forces reported 395 incidents.
The research showed that the highest number of attacks took place in Nottinghamshire, where there were 279 incidents.
At the other end of the scale the Cambridgeshire and Avon and Somerset force areas were safer, with only eight and six reported incidents respectively.
Encouragingly, the results also showed that 75 per cent of the attacks reported resulted in arrests.
Attacks 'put lives at risk'
Andy Charlton, the chief inspector for Nottinghamshire Police says the force are taking these attacks very seriously.
"Any item thrown into the path of a moving vehicle, whether it's a snowball, an egg or a brick has the potential to cause a distraction and put people's lives at risk.
"We will not tolerate this behaviour and are working hard to educate people about the potential dangers of this activity."
He added that police were increasing road patrols in the force area and installing cameras to ensure the offenders are brought to justice.
But if you do have the misfortune to have your car struck by a missile, what should you do?
Keep calm and carry on
"Being hit by a 'bridge bomber' can be very alarming," says Peter Rodger, chief examiner at the Institute of Advanced Motorists, and a former police inspector.
"You might not realise what has happened at first – you may just suddenly hear a big bang and see the windscreen crack.
"But don't panic. If just the bodywork of the car is struck you will still have full visibility.
"If, however, the windscreen is hit then it will probably crack and it may 'craze' - break up into pieces making vision difficult which is, of course, far more serious.
"But modern laminated windscreens are more robust that those of 30 years ago and probably won't shatter all over you."
If your car is struck
- Move over to the left hand lane on a dual carriageway, or the motorway hard shoulder and come to a halt.
- Once you've stopped safely, check everyone in the car is okay, dial 999 and report the crime, your vulnerable position and any casualties.
- Even if your car is not struck, but you observe people throwing missiles, it is advisable to make a call to the police to alert them. Ask a passenger to do this, or, if you're alone, pull over in a safe place to make the call.
What do you think?
Have you been hit by a motorway missile? If so, how did you react?
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