Integrated speed and red-light cameras have cut serious crashes 72 per cent, changed driver behaviour and saved the community at least $2.2 million, a review has found.
Authorities have installed the cameras at 30 busy metropolitan intersections since July 2010 and the Curtin-Monash Accident Research Centre has evaluated the effect of the devices at 11 sites upgraded from red-light cameras.
Report co-author Huei-Yang Chen said preliminary results found the combined cameras reduced all reported crashes at those intersections 19 per cent - with crashes where people were killed or hospitalised cut 72 per cent, right-angle/turn-through crashes falling 41 per cent and rear-end crashes dropping 20 per cent.
"After accounting for the initial project costs of $1.65 million ($150,000 per site) and operating and maintenance costs, the net cost savings to the community was estimated at $2.294 million," the report found.
Mr Chen said there was likely to be an improvement at intersections where previously there was no camera. Authorities say the results, which are in line with a similar Victorian study, are more evidence of the devices' role in reducing road trauma.
Sen. Sgt Tony Carabetta, from infringement management and operations, said the results put paid to the complaint that the cameras were revenue raisers.
"They're revenue-saving and they're life savers - they reduce crashes and speed through intersections," he said.
"Another benefit is a reduction in a cost that cannot be calculated - the emotional trauma suffered by families who have loved ones killed or injured in crashes."
The study also showed a fall in the number of speeding and red-light infringements issued at the intersections, with speeding tickets falling about 25 a week from an initial spike and red-light offences down about one a week.
The report found the "significant" drop in speeding might partly explain the substantial decrease in crashes at those sites. The "small but significant decrease" in infringements for running a red light at sites upgraded to the combined cameras highlighted the potential for changing driver behaviour, the report found. Road Safety Minister Liza Harvey said the results were encouraging but would not say whether any more integrated cameras would be funded.
"Any further funding for the program would be considered as part of the normal budgetary process," she said.
Mr Chen said the integrated camera sites needed to be re-evaluated when more post-installation crash and speeding data were available.
The report recommends identifying other potential metropolitan and rural sites for the devices.