Do Red-Light Cameras Work?

There are few issues as controversial as photographic traffic signal enforcement systems, more commonly known as "red-light cameras". This is a technology which reeks of "Big Brother" surveillance. The impact of the technology on the rate of accidents is ambiguous, and the motivation of city leaders is often questioned since the cameras can be a significant revenue producer for municipalities.

The level of cynicism in general is very high right now because of the corruption found in so many of our institutions. When researching red-light cameras, this is apparent not only with comments in blogs from the public, but also with state officials lack of trust in local authorities, and everyone's seeming distrust of the data from the insurance industry.

The Insurance Institute for Highway Safety (IIHS), funded by automobile insurance companies, is the strongest advocate for red-light cameras. The studies from IIHS appear to be inconsistent with studies by virtually everyone else. For example, the IIHS claims that "using techniques of meta-analysis, the ... review did not find a statistically significant change in rear-end crashes." This conclusion is clearly inconsistent with most other studies. Some news articles, and some lawmakers, accuse insurers of mixed motivations since their revenues may increase when higher premiums are charged due to crash and citation increases. But accusing the insurance industry of wishing for more traffic accidents is amazingly cynical.

It is surprising that a definitive answer on the effect of red-light cameras is so unavailable. One of the problems is the technology tends to reduce one type of wreck, the "T-Bone", a collision between cars traveling at 90 degrees from one another, but increase rear-end collisions. This is because of panicked drivers over-reacting to the presence of the cameras. This was the finding of the Federal Highway Administration in 2005. They concluded that right-angle crashes decreased by 25 percent and resulting injuries decreased by 16 percent. However, the number of rear-end crashes increased by 15 percent and injuries from those accidents increased by 24 percent. It should be noted that the T-Bone collision is frequently the more severe of the two types of accident.

Studies by the states of Florida, North Carolina, and Virginia have reported that red-light cameras are responsible for an increase in the number of accidents, as well as crashes involving injuries. "Cameras were associated with an increase of between 31 percent and 54 percent for rear-end crashes overall," the 2007 Virginia DOT Report Shows report found. "The association of the cameras with angle crashes differed among jurisdictions, although a preponderance of test results suggested an increase."

Another complication with the measurement of the rate of auto accidents in general, is that our society in the U.S. is aging, and older drivers tend to be more conservative drivers. In Florida, the injury rate from red-light running crashes has dropped by about a third in the last 10 years without red-light cameras.

Many people question the motivation of local leaders who advocate red-light cameras. Dallas officials reviewed the statistics for red-light camera generated citations, and decided that about a quarter of the cameras they had installed had resulted in a dramatic reduction in the rate of citations, so they turned them off. They were no longer sufficiently profitable.

Texas is the most recent state to consider a ban on red-light cameras.

Red-light cameras are effective in reducing total casualty crashes, but the evidence is less conclusive on total collisions. Nationally, more than 7,000 fatal crashes and more than 500,000 injury crashes occur within intersections every year. This should be reduced. Larger and better controlled studies are needed, performed by entities that have sufficient independence and credibility.

Brian Bradshaw's work incorporates more than 25 years working with advanced instrumentation and information technology. He specializes in implementing Security Camera Systems for homes and businesses in the Southwestern United States with offices in Dallas and Phoenix. For additional information, please visit us at B.V.Technology Video Analytics and Surveillance Cameras.