HOUSTON -- A study of red-light cameras installed in Houston showed traffic accidents doubled at those intersections in the first year after they were put in.

Houston Mayor Bill White defended use of the cameras, which he has favored, saying they prevented even more traffic wrecks.  Critics, however, retorted the city-financed study supports their contention the cameras are more about generating revenue than making streets safer.

Violators photographed running red lights at the 50 intersections monitored by cameras get $75 tickets in the mail.  Since September 2006, the cameras have led to at least 387,000 citations and generated more than $20 million in revenue.

“There is no scientific, documented proof that collisions are reduced with the red-light camera program,” said Mike Sullivan, a Houston city councilman who opposes the cameras. “I’ve maintained all along that the program was flawed.”

White said a 40 percent reduction in citations in October compared with the same month a year ago is “proof in the pudding” that drivers are heeding the cameras.

“Our goal is to reduce the number of people who are running red lights,” he said in Tuesday’s online edition of the Houston Chronicle.

“Collisions are going up all over the city,” Bob Stein, a Rice University political science professor and one of the report’s authors, said Monday. “But red-light cameras have held back that increase at approaches where they have been installed.”

The mayor and the study’s authors are recommending more cameras at some intersections for additional research but acknowledged comprehensive citywide vehicle crash data is not available.

Stein also acknowledged Houston police figures show the accident rate is down since 2004 but said that data is unreliable because police don’t file reports on every crash.

Researchers plan to look at insurance industry data to bolster their findings. Those results are expected sometime next summer.