Porcia London walked into the West Los Angeles courthouse ready to fight her red light camera ticket.
Unlike some drivers facing fines, the 29-year-old homemaker had not risked a deadly broadside by sailing through a stop light -- the principal safety problem cameras were intended to address. Her $159 citation came after she braked at a Manchester Avenue intersection, checked for cross traffic and made a right turn.
"I looked to make sure," she said. "I wasn't being unsafe."
In Los Angeles, officials estimate that 80% of red light camera tickets go not to those running through intersections but to drivers making rolling right turns, a Times review has found. As London realized that day in court, her turn was illegal because she did not completely stop before turning.
One of the most powerful selling points for photo enforcement systems, which now monitor 175 intersections in Los Angeles County and hundreds more across the United States, has been the promise of reducing collisions caused by drivers barreling through red lights.
But it is the right-turn infraction -- a frequently misunderstood and less pressing safety concern -- that drives tickets and revenue in the nation's second-biggest city and at least half a dozen others across the county.
Some researchers and traffic engineers question the enforcement strategy.
"I've never . . . seen any studies that suggest red light cameras would be a good safety intervention to reduce right-turning accidents," said Mark Burkey, a researcher at North Carolina A&T State University who has studied photo enforcement collision patterns.
Some county cities with photo enforcement opt not to target right turns. Others limit camera use for those citations.
"We're kind of very leery about right turns. . . . They're not really unsafe per se," said Pasadena's senior traffic engineer, Norman Baculinao. Only one of that city's seven camera-equipped intersection approaches is set up to monitor right-turn violations, he said.
"This is intended to be a traffic safety program. People who make right turns generally are going at a low speed," and resulting accidents tend to be a "sideswipe at most," he said.
Emphasizing those violations, Baculinao said, would be "more for revenue generation" than safety.
Federal Highway Administration research has found that cameras can reduce red light violations and broadside crashes but can also increase less serious rear-end accidents caused by people making sudden stops to avoid tickets. Thus far, the studies have focused solely on straight-through and left-turn crashes because they are the most serious and common, said Doug Hecox, an agency spokesman.
Right-turn collisions are a "considerably rarer thing . . . [and] tend to have less likelihood of a fatality or serious injury," he said.
Officials in Los Angeles and other cities that cite large percentages of right-turn violators -- Covina, South Gate, Lancaster, Baldwin Park, Walnut and Montebello -- say the infractions increase hazards, particularly for pedestrians. "People have this misconception that it's OK to whip a right turn on a red light," said Los Angeles County Sheriff's Deputy Jon White, with Lancaster's photo enforcement program.
Right turns at red lights have "always been associated with some danger," said transportation researcher Richard Retting of the Insurance Institute for Highway Safety. "Enforcing against drivers who don't stop at all has the potential to make intersections safer."
Cities choose which intersection approaches and movements -- left turn, straight through, right turn or a combination -- they want cameras to track, often after reviewing accident and violation data. Many cities record illegal right turns only when a vehicle is going 15 mph or faster.
The city of Los Angeles issued more than 30,000 photo tickets last year at 32 camera-equipped intersections. About eight in 10 involved right turns, said Los Angeles Police Sgt. Matthew MacWillie, the program's co-coordinator.
Improper right turns had not caused a major accident problem, said Glenn Ogura, a city traffic engineer. But they reflect bad driver habits.
"They could actually hit a pedestrian," he said. "We've been lucky, [but] it's certainly, for us, a very real safety problem."
Twenty-three of the county's 88 cities -- along with Los Angeles County and the Metropolitan Transportation Authority -- have installed red light camera systems. All red light running violations in Los Angeles County carry a hefty $381 penalty -- with one notable exception.
Tickets for improper right turns at traffic signals in the city of Los Angeles carry a fine of only $159.
Other agencies insist that they are ticketing properly, but MacWillie said the LAPD practice is long-established and appropriate.