The Problem: Annually, more than 32,000 people are killed in motor vehicle crashes, and an additional 2 million are injured in the United States. CDC: Motor Vehicle Safety Factsheet. Crashes occur due to impaired driving, inexperience, faulty vision and general recklessness. In congested areas, pedestrian safety is also a major public health concern. Motor vehicle crashes account for 20% of deaths of children ages 1-14 years old. CDC: Reducing Childhood Pedestrian Injuries.
The Law: Traffic laws are designed to minimize motor vehicle crashes and to improve driver, passenger and pedestrian safety. Enforcing traffic laws can be difficult. Red light cameras take a picture of any car that fails to appropriately abide by a red light thereby endangering other drivers and pedestrians. The pictures are used to issue traffic citations, which often include sizable mandatory fines ($446 in Los Angeles: Photo Red Light Program). Twenty-four states and the District of Columbia have red light programs operating somewhere within their jurisdiction authorized either through state or local law. Governors’ Highway Association: Red Light Cameras. For an example of a state law authorizing the use of red light cameras, see RI Stat 42-28.9
The Evidence: In a systematic review, Aeron-Thomas and Hess reviewed ten studies measuring the impact of red light cameras on motor vehicle crashes. Aeron-Thomas A, Hess, S. Red-Light Cameras for the Prevention of Road Traffic Crashes. The Cochrane Library. 2009, v.2. The reviewers found that the studies generally identified an association between the red-light cameras and reductions in fatal crashes. However, weaker and often statistically insignificant relationships were observed between the cameras and overall crashes. On this basis, the reviewers concluded that there was sufficient evidence to establish the effectiveness of red-light cameras as an intervention aimed at reducing fatal crashes, but that additional research is needed to validate the impact of these cameras on overall crashes and reckless driving generally.
The Bottom Line: In the judgment of a Cochrane Collaborative expert panel, sufficient evidence exists to support red light cameras as an effective public health intervention to reduce motor vehicle crash fatalities, but there is insufficient evidence to validate the effectiveness of the cameras in reducing overall crashes.
Additional Information: The Governors’ Highway Association provides online access to a table indicating in which states red light cameras are authorized or prohibited under state law.