Study examines use of automated photo enforcement of red light running

Deliberate running of red lights at intersections causes an estimated 260,000 crashes each year. In Florida alone, red light running caused more than 11,600 crashes, 121 deaths, and 16,000 injuries in 1996.

In spite of a variety of countermeasures used to help solve this problem-adjusting timing signals, removing unwarranted traffic signals, and traditional police enforcement-this problem goes largely unchecked due to the inability of law enforcement to adequately or safely patrol hundreds or even thousands of intersections in an urban area. Traditional enforcement requires a law enforcement officer to observe the violation, and then chase, stop, and cite the violator. This generally means chasing a driver through a red light, potentially resulting in danger to the officer, motorists, and pedestrians.

A recently-released CUTR study examines the implementation of a new method, the use of red light photo enforcement cameras, to enforce traffic laws by automatically photographing vehicles whose drivers run red lights. This method is being tested with success at several locations in states and cities across the U.S., including Arizona, Virginia, Maryland, North Carolina, New York, Los Angeles, and San Francisco. Polk County, Florida, conducted one of the first experiments with the cameras to issue warning notices to vehicle owners.

The results of various evaluation studies indicate significant reductions in red light violation rates as well as considerably improved awareness of the problem.


The technology used in automate red-light enforcement is fairly simple and straightforward. Cameras, mounted adjacent to the intersection, are connected to the traffic signal system and to inductive loops buried in the pavement. If a driver enters the intersection after the light has turned red, the camera is activated.

These high-speed, high-resolution cameras receive vehicle location information from the loops, and pictures (usually two) are taken of the vehicle and its license plate. The time of day, length of time after the light has turned red, and vehicle speed are all imprinted on the photographs, which then can be used as the basis for mailing citations to violators.

Key Issues

While there are several issues that must be resolved related to citations (vehicle driver vs. owner?, time lags), interest in red light camera enforcement is growing rapidly among state agencies and local governments. But a number of key legislative, legal, financial, and awareness issues also are being discovered and documented.

For example, in most jurisdictions, it is necessary for an officer of the law to witness a traffic infraction before a ticket can be issued. Therefore, to implement photo enforcement projects, new laws are necessary. Passing such legislation can be difficult because of several key issues, including concerns about privacy, liability (vehicle driver or owner?), and use of camera images as evidence. An attempt to pass a law allowing photo enforcement in Florida during the 1998 Legislative session died in committee.

Implementation of this enforcement requires coordination among a variety of groups, including transportation agencies, law enforcement agencies, judicial agencies, and elected officials, which can be difficult. These projects also require an understanding and acceptance by the public, and developing and conducting a community awareness campaign also requires coordination among a variety of agencies.

Significant investments are necessary to implement this technology. They include acquiring cameras, installing new loops, and conducting public awareness campaigns. Cameras can cost as much as $50,000 each, housing can cost $6,000, and loop installation costs about $10,000 per intersection. However, the investment can be recouped through receipt of fines.


Early results of photo enforcement projects across the country are encouraging. San Francisco reported a 10 percent drop in collisions and a 40 percent drop in red light violations after implementation. New York City experienced a 62 percent drop in violations. Los Angeles, the first city in the U.S. to issue tickets based on photo enforcement, experienced a 92 percent reduction in violations during a four-month pilot project at Compton Boulevard and a 60 percent reduction after a three-month project at Alondra Boulevard.

Overall, advantages of automated photo enforcement include:

  • reductions in the problems of limited enforcement resources and logistics
  • reductions in red light running and resulting accidents
  • modifications in driver behavior
  • increased citations and increased revenues
  • increased safety

However, a number of disadvantages also exist. These include:

  • dealing with legislative issues
  • complexities in selecting intersections and camera vendors
  • time lags between infractions and citations
  • the issue of citing the vehicle owner vs. the vehicle driver at the time of the infraction
  • high start-up/infrastructure costs
  • potential loss of privacy

While legal and initial investment concerns need to be addressed, the success in reducing accidents at intersections in the pilot projects being conducted around the country indicate that automated photo enforcement is a technique worth debating in Florida.

For further information, contact CUTR Research Associate Mark Burris at
(813) 974-9809, .

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