WASHINGTON (AP) — One out of every five Americans lives in a community that pays a for-profit company to install and operate cameras that record traffic violations. A pro-consumer group says that practice could end up putting profits ahead of safety and accuracy.

Some contracts require cities to share revenue with camera vendors on a per-ticket basis or through other formulas as a percentage of revenue. Suffolk County, N.Y., for example, diverts half of the revenue from its red-light camera program to its vendor, according to the report being released Thursday by the U.S. Public Interest Research Group.

Another type of agreement — conditional "cost-neutral" contracts — also contain provisions that link payments to the number of tickets issued, although the payments are capped, the report said. Under these contracts, local governments pay a monthly fee to a camera vendor. If ticket revenues fail to cover the vendor's fee in any given month, cities may delay payments. That gives vendors "an incentive to ensure a minimum (number) of citations are issued," the report said.

As many as 700 communities, with a combined total of more than 60 million people, outsource their street and highway camera systems, the report found.

While vendors capture violations, police or other local officials approve which violations are issued tickets. Some contracts penalize cities if they don't approve enough tickets, effectively setting a ticket quota, the report said. That can undermine the authority of local authorities to when to issue tickets, it said.

"Automated traffic ticketing tends to be governed by contracts that focus more on profits than safety," said Phineas Baxandall, the report's co-author.

Baxandall acknowledged that cash-strapped communities have a financial incentive to maximize the number of citations they issue even when they don't use a vendor. But local governments are also accountable to voters, whereas private vendors aren't, he said.

Red-light cameras have been effective at saving lives by deterring motorists from running lights, said Anne Fleming, a spokeswoman for the Insurance Institute for Highway Safety.

An analysis by the institute showed they saved 159 lives from 2004 to 2008 in the 14 biggest U.S. cities with cameras. If cameras had been operating during that period in all cities with populations of more than 200,000, 815 fewer people would have died, the institute estimated.

But Baxandall said research on the effectiveness of the cameras is unsettled. Some studies, he said, show motorists who are aware of the cameras sometimes cause injuries by slamming on their brakes to avoid being caught running a light.

Some red-light camera vendors have created and bankrolled organizations like the National Coalition for Safer Roads that appear to be grassroots civic groups, but which mainly promote greater use of red-light cameras, the report said.

David Kelly, president of the safer roads coalition, said the flaw in the research group's study is that vendors don't create traffic violations — motorists do.

Vendors "aren't creating a market. The people running the red lights are creating the market," he said.

"We have saved lives," said Kelly, a former acting head of the National Highway Traffic Safety Administration under President George W. Bush. "Do we want to have more people dying at intersections because they are running red lights, or do we want to do something about it?"

The move to privatize red-light camera and speed camera enforcement is part of a larger wave of outsourcing of government services, Kelly said.

"We have private industry all across traffic safety," he said.

The traffic enforcement industry has amassed significant political clout that it uses to shape traffic safety regulation nationwide, the report said. Camera vendors are aggressively lobbying to expand authorization for private traffic law enforcement to more states, and are marketing enforcement systems to more communities, it said.

About half of states have authorized the use of red-light cameras.

Camera vendors employed nearly 40 lobbyists this year in Florida whose agenda included killing a bill that would have required communities to adopt longer yellow light times to increase intersection safety and killing a separate bill that would have banned red-light camera systems, the report said.

Kelly said the research group also lobbies.