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.
"When you're doing 40 miles per hour on a straight-through violation, the likelihood of causing a serious or fatal [crash] is much greater," MacWillie said. During right turns, "most people have control of their vehicle. . . . If they see another vehicle or pedestrian, you're able to react and stop in time."
Montebello officials say their city's camera program -- which involves mostly right-turn tickets -- is about safety, not money.
Still, Superior Court estimates show that Montebello's cameras have one of the county's highest revenue-generating rates, bringing in about $90,000 per month from five approaches to three intersections.
On a per-approach basis, that is three to four times the amounts collected in some cities, where officials say photo ticket revenues have declined and basically cover system costs. At this point, Montebello's camera program brings in about two times its expenses.
In the eastern San Gabriel Valley, Walnut's cameras cover two approaches at a single intersection: Grand Avenue and Amar Road. Other movements are monitored, but the bulk of tickets issued are for right turns, said Los Angeles County Sheriff's Sgt. Brad Gray.
Walnut's system netted about $250,000 in 2007, its first year of operation, said Chuck Robinson, assistant to the city manager. Right-turn enforcement was included, records and interviews show, after camera vendor Redflex Traffic Systems surveyed several intersections and set a "threshold" of violations needed to make the cameras financially feasible.
"It had to meet that," Robinson said, and right-turn violations helped.
A Redflex spokeswoman said the company takes "absolutely no position" on whether right turns should be cited. Robinson said violations are down, which is the goal.
Some experts caution that violation rates aren't necessarily the best measure of intersection hazards or improvements.
"From an engineering standpoint, we know the locations we would want are different than what the [camera] vendor would want," said Stephen Yanez, a Downey engineer. "They are basically looking for locations that have a high violation rate. We are looking for locations with a high collision rate. . . . Collision rate is not necessarily related to violation rate."
Using cameras to police right turns offers a "tremendous opportunity for revenue" because the violation is common, he said. But he added that the turns involve relatively little accident risk.
"That's why people are doing it," he said. Downey turned down a red light camera proposal because of uncertainty about the effects on traffic safety and revenue, records show.
Motorists often are confused and complain about right-turn photo tickets, police say. John Jasso, a Pasadena technology manager, said he didn't fully get the complete-stop rule until two right-turn photo tickets came in the mail a week apart.
One was before sunrise on a Saturday morning. The streets were largely deserted, he recalled, as he braked and rounded a corner heading to the Montebello golf course.
The second ticket, before the first arrived in the mail, involved another early trip to a golf course, he said.
"I was like, 'They've got to be kidding me.' Especially at 6 in the morning," he said. The first ticket cost him $381; the second was dismissed because of a paperwork error, he said.
Jasso thinks focusing cameras on right turns is mostly about generating cash.
But he admits it changed how he approaches signalized corners.
"Now I stop every single time," he said. "No matter what time of day or night."