Ari Ashe, wtop.com
WASHINGTON - A new study from the Insurance Institute for Highway Safety finds that cameras in Arlington County have proven effective at reducing the number of drivers committing red-light violations, along with reducing violations that could cause a crash.
However, its findings are disputed.
Researchers for the study analyzed four intersections with red-light cameras in Arlington County, four nearby intersections in Arlington without cameras and four intersections in Fairfax County without cameras.
The intersections included parts of Lee Highway, North Glebe Road, Braddock Road and Old Keene Mill Road, among others.
The report found violations occurring at least 0.5 seconds after the light turned red were 39 percent less likely one year after ticketing began than would have been expected without cameras, according to the institute. Violations occurring at least 1 second after were 48 percent less likely and the odds of a violation occurring at least 1.5 seconds into the red phase fell 86 percent.
A reduction rate of 80 to 90 percent shows a successful red-light camera program, says AAA Mid-Atlantic spokesman John B. Townsend II.
"What these numbers show is that those violations (that) most likely to lead to a crash are reduced the most," says Anne McCartt, senior vice president for research at IIHS and the study's lead author.
"The longer the light has been red when a violator enters an intersection, the more likely the driver is to encounter a vehicle traveling in another direction or a pedestrian."
However, a website called TheNewspaper.com -- which describes itself as "a journal covering motoring issues around the world from a political perspective" -- disputes the IIHS conclusions.
The site says a separate, 2004 study by the Texas Transportation Institute found that right-angle crashes from red-light running -- "the type caused by straight-through violations of red signals at intersections" -- typically occurred at least 5 seconds after the signal turns red.
"The IIHS data suggest red light camera violations generate the most revenue for inadvertent violations that take place when conflicting traffic is held by an all-red period," the website states. "With the cameras operational, 90 percent of all violations occurred in the first 1.4 seconds that the camera was active and accidents do not happen. A total of 61 percent of the violations represented even more minor, split-second violations between 0.5 and 0.9 seconds after the light turned red."
Under Virginia law, drivers have a half-second grace period after the light turns red.
"Our big concern is whether you're catching aggressive red-light runners or inadvertent red-light runners," says Townsend. "At 0.5 seconds, you may be catching a lot of unintentional red-light runners who didn't gauge the yellow light correctly and didn't clear the intersection."
Critics further point out that many tickets from the red-light cameras come from rolling right turns, or drivers who don't completely stop before turning right, even though a right turn on red is permitted.
"The law says you have to come to a complete stop, and then you can turn right on red. It's an easy thing to do. The way to avoid those tickets is count one, two, three, then make the turn," says Townsend.
The full IIHS study can be read here.
This story has been modified to say the study found a decrease in violations that could cause a crash, instead of saying the study found a decrease in the number of possible serious crashes.
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