Red light cameras are a booming business in the capital region - bringing in at least $18 million in one year, the News4 I-Team found.

But some experts say if they’re really doing their job, the cameras ought to put themselves out of business.

Hugh McGee is a traffic safety consultant with the Institute of Transportation Engineers, which created the formula used to time traffic lights. “There is a role for red light cameras,” he said. “They've been proven to be effective."

McGee says cameras can make intersections safer by changing driver behavior. "To be effective you would see the income going down to where perhaps you're only covering the cost of the system. You're not realizing a profit."

In fact, some communities have eliminated their programs, including Fairfax, Va. in 2005 and Bowie, Md. in 2007.

But Prince George’s County is increasing the number of red light cameras in use. “We’re going to 72 from 23 active right now,” said Major Robert Liberati of the Prince George’s County Police Department.

He says he doesn’t ever see the program going away because the county has the highest number of traffic fatalities in Maryland. "With nearly 500 square miles there's a lot of intersections a lot of roadways that need to be covered," he said.

Major Liberati says the county is looking at mobile red light cameras as well. “Once it's achieved its goal and traffic is now compliant, it's time to move on."

DC’s police chief also said the cameras are also here to stay, even if the violations drop.

"We're going to keep expanding. I think the technology is good,” Chief Lanier told the I-Team. “For us they'll probably never put themselves out of business because we have a lot of people that come here from all over that are traveling in and out of the cities."

The News4 I-Team wanted to know which cameras raked in the most money in each jurisdiction. In 2011, they were:

Arlington, Va.: At the intersection of Fort Myer Drive and Lee Highway, $244,600

Alexandria, Va.: Patrick and Gibbon streets, $373, 650

Montgomery County, Md.: River Road and Wilson Lane, $336,225

Prince George’s County: Pointer Ridge Drive and Route 301, $373,050

Washington, D.C.: South Capitol near I Street SW, $743,280

SEE A MAP of how much money each red light camera in the Washington, D.C. area brings in.

The camera on South Capitol Street in the Southwest section of the district brought in more money than any other in our region. But Chief Lanier insists it’s not about the money.

Instead, she said, it’s about safety.

She plans to expand the automated enforcement to other areas like stop signs.

"I can use my police officers more for crime,” Chief Lanier explained. “I can make sure my officers are safer doing their job. And I can increase safety for people in the community. It's a win-win all the way around for me."