ATLANTA — Surveillance cameras at major intersections dramatically reduce the number of drivers who barrel through red lights, two new research reports say.

The findings come as debate about the controversial devices continues a decade after they were introduced. The battles include a proposal to ban the cameras in Georgia, litigation in at least three states and legislative efforts to permit them in six other states, including Hawai'i.

The cameras automatically photograph vehicles that drive into intersections after the light turns red. Vehicle owners are then mailed citations instructing them to pay a fine or sign an affidavit that they weren't driving at the time.

More than 850 people die and about 170,000 are injured each year in crashes caused by drivers running red lights, the National Highway Traffic Safety Administration says.

In Hawai'i, the state Legislature repealed its "van cam" law in 2002, just months after it took effect, after overwhelming opposition from motorists. The law authorized a private company hired by the state to place vans alongside highways to photograph speeders and mail them tickets.

State Rep. Joe Souki, D-8th (Wailuku, Waihe'e, Waiehu), chairman of the House Transportation Committee, was behind the van cam law and he now wants to give counties the option of using cameras to catch speeders. His bill is being debated this session.

Others have cited speeding as a factor in the recent rash of pedestrian fatalities on O'ahu.

DRAMATIC CHANGE

Researchers studied the effectiveness of red-light cameras in Philadelphia and Virginia Beach.

The Philadelphia study, conducted by the Insurance Institute for Highway Safety, an industry group, examined red-light violations using a two-step approach.

First, researchers found that violations dropped by 36 percent after yellow lights were extended to give drivers more warning that the light was about to turn red. After red-light cameras were added, remaining violations dropped by 96 percent.

"There's a dramatic change in driver behavior when red-light cameras are used," says Richard Retting, senior transportation safety engineer for the Insurance Institute for Highway Safety. "The jury is in on that question."

The Virginia Beach study, conducted by Old Dominion University, examined signal violations at four intersections before red-light cameras were installed, while they were operating and after they were removed in 2005. Violations more than tripled by August 2006.

"That's a huge jump," says lead researcher Bryan Porter, an associate professor of psychology at Old Dominion. "The rate of red-light running was actually higher" than before the cameras were installed.

COURT OF PUBLIC OPINION

The popularity of the cameras is growing rapidly despite opposition that centers on constitutional grounds. About 250 communities around the United States use the devices, according to the Insurance Institute. Just 10 years ago, only New York and San Francisco had them.

Opponents say the cameras deny drivers their right to confront their accusers in court and are a ploy by local governments to raise revenue.

"There is a lot of money to be made with them," says Howard Bass, a Minnesota attorney who successfully challenged Minneapolis' red-light camera system in a case that will be argued before the state Supreme Court next month.

"Ultimately, this is an issue that may have to be decided in the court of public opinion rather than courts of law. It's a public policy issue of how much surveillance creep we will tolerate in the 21st century."