PHOENIX - Arizona cities that want to install or keep using photo enforcement equipment on state roads are going to have to prove the cameras do more than generate fines.

Without debate, the House on Monday gave final approval to legislation saying communities can place photo speed radar and red light cameras on state highways only if they first prove it is "necessary for the public safety of the state." It now goes to the governor for her signature.

State routes are numbered highways, such as Arizona 77, more commonly known in Tucson as North Oracle Road, where one of the more-controversial cameras has been placed at the intersection with West River Road.

The new requirement means local governments must prove the device will be a safety improvement. Without that proof, the state Department of Transportation, which has final say over use of the roads, would be precluded from giving the go-ahead.

Lawmakers agreed to alter the final version of HB 2477 to deal with the fact there already are cameras set up along roads in several communities. Sen. Steve Farley, D-Tucson, said he was concerned the legislation would make it impossible for any city to show the installation will actually result in further improvement in safety.

So now the legislation requires a city that already has speeding or red-light cameras installed to show what their impact has been, by comparing accident rates before installation with what is occurring now. But it still leaves ADOT with the power to order removal if the agency determines the photo enforcement system "does not maintain a positive impact on public safety."

The measure is a victory of sorts for supporters of photo radar. It means that lawmakers will not take up more far-reaching proposals to ban the use of automated enforcement systems on state roads.

And HB 2477 does not disturb the ability of counties, cities or towns to establish photo enforcement systems on their own locally maintained roads.

The legislation stems from a belief among some at the Capitol that the cameras are designed less for public safety and more to generate citations - and the fines that come with them that enrich city coffers.

Rep. Debbie Lesko, R-Glendale, who drafted this measure, said this will ensure that at least the cameras placed on state highways have a legitimate purpose.

ADOT officials acknowledged that, until now, they have basically allowed cities and towns to erect cameras where they want on state roads.

Most are simple photo-radar devices, designed to catch speeders.

But ADOT has allowed Tucson to erect cameras at Oracle and River roads to spot those who run the red light there. Because of the irregular configuration of the intersection, the light has been an ongoing source of controversy since it was put in five years ago.

"If the city completes all of the permit requirements, the permits are granted," agency spokesman Tim Tait said. The only issue for ADOT is to ensure any installation complies with engineering safety standards, he said.

Lesko's measure still leaves ADOT with some discretion on granting or rejecting a request. But the agency will first be required to review the number of vehicles operating each day on that stretch of the road, the percentage who violate traffic laws and any reports of motor vehicle accidents.

ADOT has existing agreements with Tucson, Chandler, El Mirage, Globe, Superior, Show Low and Star Valley. Tait said Sierra Vista and Casa Grande are working with ADOT to install photo enforcement cameras on state roads in their communities.