The man is Sydney manufacturer Ami Gale, 58, who was travelling at 100km/h in Camden man Greg Ackman's 1997 Mitsubishi Triton ute at 12.35pm on October 31 when the half-brick was thrown through the truck's windscreen.

Luckily for Mr Gale, it hit the windscreen at its base and not higher up.

Mr Gale said he saw something like a shadow from the top of the bridge and then, as he said: ``Bang!''

``If it had been 20cm higher, it would have penetrated the glass on to my face,'' Mr Gale said.

``And if it had been a split second later, then I probably wouldn't be talking to you.''

Mr Gale was returning to Sydney on a journey that he usually makes on a scooter.

The RTA has built fencing at the overpass to try to prevent such attacks, but Mr Gale says cameras should be installed to discourage anything like that happening again.

Greg Ackman agrees.

``If someone will have their picture taken (at these overpasses), then I think they'd think twice about doing it,'' Mr Ackman said.

An RTA spokesman said: ``The RTA has no plans to install security cameras on the overpass.''

Macquarie Fields local area command crime manager Mark Brett said police were always concerned about this type of behaviour.

Detective Chief Inspector Brett said: ``We encourage two things; ensure that your children aren't involved in throwing any sort of missiles, and if the motorist does see children or young people or any person undertaking such an incident, contact the police immediately.''

Anyone with information about the incident is asked to call Macquarie Fields police on 9605 0499.

REMEMBERING AN 11-YEAR-OLD TRAGEDY

It was on August 23, 1998, that Ingleburn man Mark Evans was killed on the M5 in a rock-throwing attack by two men and a teenager.

A father of two, Mr Evans died instantly when a concrete block smashed through the window of his semi-trailer near Menangle.

The Glenlee Road overbridge he was passing under has since been named in his memory.

The three culprits - then aged 27, 21 and 17 - had balanced a 20kg concrete block on the guard rail of the 7m high overpass and waited for a target.

They were imprisoned after pleading guilty to manslaughter.