Rockville red-light cameras nabbed nearly 18,000 drivers last year, a 105 percent spike from 2011 that some say was derived from unfairly cashing in on uninformed drivers.

The city issued 17,794 tickets based on incidents caught by the cameras in 2012, an increase from the 8,638 tickets given in 2011, a newly released study found. That spike generated more than $1.3 million from motorists.

But John Townsend, a spokesman for AAA Mid-Atlantic, said the number of tickets from the red-light cameras only grew because drivers didn't know they were supposed to come to a complete stop when turning right at a red light. The previous set of cameras Rockville used -- which were replaced in May -- didn't photograph drivers making rolling right-hand turns.

"When you highly publicize that you have cameras to crack down on people running red lights, by the same token, you should tell people the new ones are ticketing for rolling right turns," Townsend said.

And though the practice is in line with city law, Townsend contends it's in violation of a Federal Highway Administration policy that says the use of red-light camera stop lines, road markings signaling where to stop at a red light, don't meet national standards for traffic control devices.

City officials, however, maintain that their use of the cameras is consistent with Maryland law, which requires drivers to come to a complete stop before turning right on red.

Maj. Michael England, with Rockville City Police, attributes the jump to the high number of drivers who don't make a complete stop before turning right at a red light. Motorists are stopping with all four tires ahead of the white stop line, England said, so they're illegally sitting in an intersection or crosswalk, and the camera captures it.

Those motorists photographed running red lights or making illegal right turns receive a $75 ticket in the mail, accompanied by photographs showing their vehicle before and after the light changed.

The process is upsetting to Montgomery County resident Robin Ficker, who said the cameras are catching drivers making innocent mistakes rather than motorists intentionally driving recklessly.

"Revenue is their No. 1 driver," Ficker said. "I just don't think there are 17,000 drivers in Rockville who want to drive unsafely. They're calling people lawbreakers who aren't lawbreakers."