AAA has long criticized fee arrangements used by the city and elsewhere that pay the contractor a cut of each $40 citation, arguing that it creates incentives to process more tickets.

Others see such an abundance of problems that they think the city could owe millions of dollars in refunds to vehicle owners if the speed cameras were challenged in court. Steven A. Glazer, a federal administrative law judge who has written about Maryland's cameras, believes the city's program is so legally problematic that many of the speed camera fines should be returned to drivers.

"They should refund them with interest, absolutely," said Glazer, a University of Maryland adjunct law professor who wrote a law journal article about the cameras this year. "Since the jurisdictions are expecting people to follow speed limits strictly, then they should follow the law implementing speed cameras equally strictly. We expect them to act the same way they've treated us."

Glazer said he and his family have received two dozen speed camera tickets in the area the last six years – none in Baltimore – and got nine of them dismissed.

The city's speed program has come under increasing scrutiny during the last few months. Rawlings-Blake recently created a task force to examine automated camera enforcement, the city announced it will replace its camera contractor and officials began an internal review of the Cold Spring camera's accuracy.

North America's biggest camera network

Until several years ago, a speeding ticket in Maryland always meant a paper citation that a police officer handed a driver through a rolled-down window after a traffic stop. Today, jurisdictions across Maryland have delegated much of their speed enforcement to automated cameras, which announce themselves to motorists with a bright flash in the instant that the photos are taken.

About 40 jurisdictions in the state have the cameras, from rural Eastern Shore towns to major population centers, according to the state comptroller's office. Maryland is one of 13 states, along with the District of Columbia, that use them.

Montgomery County was the first to adopt speed cameras, starting in 2007. Two years later the General Assembly, at the urging of Gov. Martin O'Malley, permitted the devices statewide in school zones and highway work zones.

The law set fines at $40 — well below the cost of a traditional speeding ticket — and decreed that violations cannot be reported to insurance companies or used to levy "points" on a driver's license. The cameras' use in school zones is restricted to weekdays from 6 a.m. to 8 p.m., while in work zones they can operate around the clock. By law, all tickets issued to Maryland drivers must be mailed within two weeks to be valid.

Baltimore City, which has had red-light cameras since 1999, jumped into the program quickly and aggressively. According to Xerox State and Local Solutions Inc., which manages speed cameras for the city and other governments in Maryland and around the country, Baltimore has the largest combined speed and red-light camera program in North America.

The city has collected more than $38.6 million in speed camera fines. Roughly $10.4 million was paid in fees to Xerox, which gets up to $19.20 for each ticket the system issues. The company, which also manages the other camera programs in the Baltimore area, is slated to lose its contract with the city in January, after officials concluded that another company, Hanover-based Brekford Corp., would generate more money for the city.

Most of the rest of the ticket money has gone toward programs for traffic safety and management, snow removal and street lighting, city officials say. Last year's unanticipated revenue will be used for one-time projects, such as improvements to intersections with numerous accidents.

To examine the impact of speed cameras in the Baltimore area, The Sun compiled data for more than 2.5 million citations issued since 2009 by Baltimore, Baltimore County and the State Highway Administration. Officials in Howard County, the only other area government that uses speed cameras, refused to provide comparable data, disagreeing with their counterparts in other counties by concluding that state law prohibits the disclosure of license plate numbers.

Just the process of gathering the information revealed the government's uncertain grasp of its lucrative traffic enforcement system.

Officials with the SHA twice released data to The Sun that contained tens of thousands of errors and omissions and, when asked to explain, said they had to check with Xerox, which keeps all of the government's speed-camera records. This spring the city released data on 736,000 citations, calling it comprehensive, then weeks later gave The Sun other records putting the total at 1.1 million tickets. Asked to explain the increase, city officials declined.

The available numbers reveal a dogged and prolific enforcement operation. And while Baltimore County and the state highway agency use the devices, the city's camera network dwarfs the others. The 1.5 million tickets issued through mid-October by the city are more than the other districts combined regionally, and its records reveal problems not found elsewhere.

A single speed camera, positioned on a busy street, will routinely record dozens of violations a day. Some in Baltimore have notched more than 800 in one 14-hour day, or one per minute.

When they're in operation, few transgressors are spared. Emergency vehicles get a pass while responding to calls, and state law exempts rentals and cars with long-term leases or dealer tags. The state also doesn't go after cars with Canadian plates.

For most other vehicles, a drive past one of the cameras at 12 mph or more over the speed limit quickly results in a citation sent through the mail. And those citations have quickly supplanted traditional tickets as the primary speeding enforcement mechanism across the Baltimore area, records show.