Red-light cameras save lives but result in more crashes that cause property damage, a new study says, as drivers slam on their brakes at camera intersections to avoid tickets, causing chain-reaction crashes from behind.

Researchers at the University of Florida College of Public Health say the findings, based partially on statistics from Toronto's red-light cameras, show the program is flawed. "Before and after" studies of 38 red-light camera intersections in Toronto revealed collisions resulting in death or injury dropped 18.2 per cent. But property damage-only collisions rose 4 per cent.

A wider look at all six Ontario municipalities with red-light cameras, including Toronto, showed that fatal and injury crashes dropped by 6.8 per cent while property damage collisions were up 18.5 per cent.

The Florida researchers, whose review included studies in North Carolina and Virginia as well as Ontario, noted that "increased rear-end crashes were a particular problem and may occur as drivers attempt to stop abruptly in order to avoid a ticket."

The researchers suggested Florida could be asking for trouble if it introduced red-light cameras because of the state's high number of elderly drivers who are more likely to be injured or killed in a crash.

Toronto politicians say the drop in deaths and injuries here is enough reason to keep the cameras.

"Our documentation shows that in Toronto it's been a sensational success," said Councillor Glenn De Baeremaeker, chair of city council's public works and infrastructure committee. "Red-light cameras are saving people's lives, saving people from being maimed and injured," De Baeremaeker said.

He hadn't seen the Florida study but doubted it would change his view. "Myself and our staff will read it in detail, but its findings are completely contrary and completely at odds with everything we've experienced in the city of Toronto. We have nothing but praise and good things to say about the red-light camera program."

While the number of property damage collisions increased, De Baeremaeker said it was important to look at the types of crashes.

The Toronto experience showed a 26.2 per cent drop in "angle" or T-bone crashes, while rear-enders were up 10.1 per cent. Province-wide, angle crashes dropped 25.3 per cent while rear-enders increased a whopping 49.9 per cent.

"The T-bone accidents have gone down," De Baeremaeker said. "Those are the most dangerous."

Toronto has also seen an increase in rear-end collisions, but the program has achieved its objective of reducing severe collisions, city officials said in a report.

The new pedestrian countdown signals may be helping to reduce crashes at intersections, said Councillor Shelley Carroll, a member of the public works committee.

"Instead of seeing `Don't Walk' and speeding up, people are seeing the seconds tick down," Carroll said. "You're at the threshold when you can see the countdown begin, so it makes more sense to stop than to gun it."

Carroll said the city has no reason to re-think red-light cameras.

"We've had positive reasons to continue the program," she said. "Over all, we've been pleased."

In addition to Toronto, Ontario municipalities with the cameras include Hamilton and Ottawa, and Halton, Peel and Waterloo regions.

Researchers looked at accident data from 1995 to 1999, before red-light cameras, and compared the results to data from 2001 and 2002, after the cameras began operating.