PHOENIX - Gov. Jan Brewer signed legislation Wednesday that could curb future photo-radar installations on state highways, and maybe even force removal of some of them there.

The law eliminates the ability of cities to set up speed and red-light cameras on state roads with little more than perfunctory state oversight. Instead, cities will have to provide statistics to prove the devices will make a real difference in safety.

Already installed photo-enforcement cameras will be allowed to stay through the end of their current permit. But at that time they will have to come down unless there is evidence their presence has reduced speeding and accidents.

Brewer has never been a big fan of photo enforcement.

When she became governor in 2009 she inherited a contract Janet Napolitano, her predecessor, had signed with Redflex Traffic Systems to place 100 fixed and mobile speed cameras along state roads.

Brewer was critical of photo enforcement, particularly because Napolitano used estimated new revenues from the cameras to close a state budget gap.

"I certainly don't support photo radar as a revenue-generating solution to solving our budget," Brewer said. "And I believe that's what it initially was put in (the budget) for."

She killed the Redflex contract in 2010.

The new law in some ways mirrors Brewer's beliefs, in that it preserves the right of cities to petition to put photo cameras on state roads if they can justify it from a safety perspective. But it is designed to preclude their placement if the main goal is to raise money from traffic citations.

ADOT currently has agreements with seven cities, including one for a red-light camera at North Oracle and West River rods in Tucson.

Nothing in the legislation precludes cities from erecting red-light and speeding cameras on their own local streets that are not part of the state highway system.

"I certainly don't support photo radar as a revenue- generating solution to solving our budget. And I believe that's what it initially was put in (the budget) for."

Gov. Jan Brewer