MIAMI, which counted on $10m (€7.2m) in fines from motorists caught on camera running red lights, is planning to lay off some workers in part because penalties didn't come close to forecasts as drivers began obeying the law.
Houston, where voters banned cameras in November, will receive about $10m less than anticipated and faces a potential claim from American Traffic Solutions Inc for cancelling a contract.
The Los Angeles Police Commission has voted to let its agreement with American Traffic expire, citing the expense.
Since cameras began spying on US motorists in the late 1980s, they've faced lawsuits challenging their constitutionality, been banned and restricted by legislation.
The number of municipalities with cameras has doubled to 539 since 2007, according to the Insurance Institute for Highway Safety.
"This is about money and not about safety," Ted Hollander, a Florida attorney who defends people charged with traffic offences, said in an interview.
Redflex Holdings Ltd, an Australia-based camera supplier, successfully defended itself against lawsuits challenging its product in 10 states last year and legislation that would ban them in six, according to its annual report.
An Arizona employee of the company was shot and killed while monitoring a speed-detecting camera in 2009.
"Photo enforcement is very much a battleground," said Gary Biller of the National Motorists Association, a drivers' rights organisation.
Its website lists 10 reasons for opposing cameras, including that vehicle owners who get tickets in the post may be forced to snitch on friends or family who borrowed their car.
Studies diverge on whether cameras, which have been endorsed by the World Health organisation, actually reduce traffic accidents.
A September 2007 review by the US National Highway Traffic Safety Administration concluded they reduced fatal side-angle collisions.
It also said less serious rear-end collisions increased as drivers braked after spotting cameras.
"These cameras are never installed as revenue generators," said Charles Territo, a spokesman for American Traffic. "They are installed with the purpose of enhancing public safety." Most contracts are "cost neutral," he said.
"A city will never pay more in fees than the cameras generate," he said. "If a camera is contracted at $4,000 a month and it generates $6,000, they pay $4,000. But if they generate $2,000, they only pay that."
In Florida, where legislation allowed cameras in last year, American Traffic donated $159,000 to state candidates and political parties during 2010 elections, according to the Florida Elections Division.
Miami planned for $10m from 32 cameras installed this year. Instead, projected revenue is less than $2m, Mayor Tomas Regalado said. The shortfall will contribute to a $15m projected 2012 budget deficit that may force the city to give employees unpaid leave off one day a week.
Visibility of the cameras and news coverage led to fewer violations, a 25pc reduction in accidents and less revenue.
"They worked too well," Mayor Regalado said.
Los Angeles has seen a 62pc reduction in red light-related collisions since 2004 and no increase in rear-end crashes, according to a report.
American Traffic, which supplied Miami's cameras, had 19 cities sign up in the first six months of this year. Goldman Sachs Group is a stakeholder.
Redflex's stock plunged 30pc in May after shareholders rejected a takeover offer from Macquarie Group Ltd and Carlyle Group, a private-equity firm. (Bloomberg)