As red-light traffic cameras spring up at intersections across the country, critics are raising questions about whether the devices actually deter red-light running, or are just a way for local authorities to make a quick buck.
The cameras snap pictures of vehicles that run red lights. The violator then receives a summons in the mail for the infraction.
There's no exact count of how many cameras are being used, but one recent study shows that they are currently used in more than a dozen states and more than 70 cities across the country.
Proponents say the cameras make roads safer by deterring red-light runners from breaking the rules, but detractors say dangerous intersections are the result of engineering deficiencies and the cameras are just a way to increase revenue on the backs of unsuspecting drivers.
"Red-light cameras just reward cities for bad engineering," said Eric Skrum, spokesman for the National Motorists Association, a motorist advocacy group that has been arguing against the use of red-light cameras nationwide.
The group contends that the best remedies for dangerous intersections are engineering improvements like longer yellow lights and shielding signals to prevent glare and make the lights more visible as the sun sets.
According to the group's Web site, the organization believes that "with properly posted speed limits and properly installed traffic-control devices, there is no need for camera-based traffic law enforcement devices."
NMA points to studies of red-light cameras that show that while there is generally a decrease in side-impact collisions, there is an increase in rear-end collisions as drivers slam on their brakes to avoid running a red light.
Robert Sinclair, a spokesman for AAA's New York office, says the risks are too great not to have the cameras in certain areas.
"The nature of the collision that takes place when someone runs a red light is a very dangerous one, the so-called 'T-bone,' " he said. "The weakest part of a vehicle is its side. So someone runs a red light and smashes into the side of a vehicle and lots of bad things can happen."
But Skrum argues that the cameras are not the only way to deal with dangerous intersections.
"Most drivers don't want to run red lights," said Skrum, "but due to engineering flaws at some intersections, they sometimes have no choice."
A number of studies have shown that by simply increasing the length of "amber" or "yellow" lights, dangerous intersections can be made safe.
"By increasing the length of yellow lights," Skrum explained, "you can cut down on the amount of violations and accidents at an intersection."
It's the moment for a driver when he must make a choice. As a light turns yellow, he has to decide between speeding up to get through an intersection or trying to stop in time to keep from running a red light.
Sinclair said that time of dilemma is shortened if a yellow light is too quick. "It might actually encourage people to try and run the yellow," he said. "It's that go, no-go decision time we worry about."
Studies show that lengthening the amber light gives drivers more time to make that choice and more time to brake.
But in some cash-strapped communities, shorter yellow lights at intersections equipped with red-light cameras means more tickets -- and that means more money.