But Mr Olsen has accused the RTA of waging a "dirty tricks campaign'' to discredit his cheaper school zone lights, which were installed at Balgowlah Heights Public School where Sophie Delezio, 7, was struck at a pedestrian crossing in 2006.

Mr Olsen's system has successfully operated at several schools including those at Peakhurst and Lugarno.

An authority spokesman rejected claims by Mr Olsen that his lights could be installed and maintained safely for $1000 while the RTA system cost $58,000, and also labelled them "unsafe'' and `"unreliable''.

The spokesman said the RTA system cost between $10,000 and $13,000 per set, with the remainder of the funding used for the set up and installation of the central computer system, ongoing maintenance, site surveying, design and other costs.

He saidmore than 260 school zones would have flashing lights by the end of the year.

"Unlike RTA's flashing lights technology, Mr Olsen's flashing lights are not connected to a central system which controls the timing and operation of lights and alerts the RTA to any problems immediately,'' the spokesman said.

However, NRMA motoring and services local director David Bentham has backed Mr Olsen and called on the Government to fast-track its roll-out of lights at school zones, saying 100 a year for the next four years was "too slow''

"The Government promised to put the money raised by school zone cameras back into school safety,'' he said.

"These cameras generated more than $45 million in 2007 alone, but the Government has only committed $46.5 million over four years to flashing lights,'' Mr Bentham said.

Only 5 per cent of the state's 3100 schools have a flashing light system.

Mr Olsen said his fully automatic signs, which have two flashing lights on each side of the words ``Check Speed'', had been fully approved by the RTA for use in traffic management, and were installed on private property next to school zone signs.

"The lights I installed are the only model that have operated with 100per cent reliability since the start of the RTA's 2007 trial,'' Mr Olsen said, adding that they were funded by businesses, and cost schools nothing.

"Unlike RTA's flashing lights technology, Mr Olsen's flashing lights are not connected to a central system which controls the timing and operation of lights and alerts the RTA to any problems immediately,'' the spokesman said.

What do you think of the flashing lights?