A quarter of motorists have had their vehicles hit by a various missiles over the past five years, according to a recent survey conducted by Autoglass.
The announcement comes as the company reflects on data gathered from a separate Freedom of Information request.
The request, submitted after two attacks on the A12 in December, found motorists face hundreds of incidents involving objects being hurled from bridges each year.
Ten English police forces who responded to the request reported a total of 395 incidents of rocks, stones and other objects being thrown at motorists or moving vehicles during 2011.
Lancashire Police recorded 125 incidents, with the Northumbria and Nottinghamshire forces both reporting 64 instances.
Suffolk Police said 15 of their 28 incidents last year related to objects thrown from bridges.
Previous data for 2010 - from nine police forces - showed there were 457 such attacks on motorists and moving vehicles.
Car insurance offers vital protection to victims of such attacks, who may suffer serious damage to their vehicles.
Autoglass managing director Matthew Mycock said: "We know from the experience of our own technicians that missile attacks are a growing problem and a recent Autoglass survey found that a quarter of motorists have had their vehicles hit by a missile of some sort in the last five years."
Copyright Press Association 2012