Refuting the Oxnard Study

The National Motorist’s Association has posted a very nice critique of the Oxnard study. Here’s a few excerpts:

Critique of IIHS 2001 Oxnard Study

The Insurance Institutue for Highway Safety (IIHS) has been one of the most vocal proponents for Red Light Cameras. Their 2001 Oxnard Crash Study has been touted as conclusive proof that Red Light Cameras have a positive effect on traffic safety. However, when scrutinized, the study fails to prove anything. Many different organizations have examined it and found it to be faulty. The following is just the latest example of an objective source recognizing and reporting the many flaws.

This report was created by the California Senate Committee on Privacy, Dana Mitchell principal author.

The Oxnard Study One of the first cities in the country to use automated enforcement technology was Oxnard, California. On July 1, 1997, Oxnard implemented automated enforcement cameras at 15 intersections throughout the city. The stated goal was public safety. At the time, “Police officials said the new system will prevent car accidents. ‘In 1996, there were 220 car crashes attributed to drivers trying to beat the light in Oxnard, said Joe Genovese,’ traffic engineer. ‘As the number of citations increases, we’re hoping we’ll see the number of traffic accidents decreasing,’ he said.” Neely, Pictures worth weight in safety Candid Cameras: Devices capture drivers running red lights to tune of $104 fine, Ventura County Star, (July 1, 1997) page A03.

Almost immediately after the Oxnard automated enforcement program began, researchers from the Insurance Institute for Highway Safety began to study the effects of these “red light cameras” upon Oxnard resident’s driving behavior. In 1999 the results of their efforts were published. ( See: Retting, R.A., et al, A.F. 1999, Evaluation of red light camera enforcement in Oxnard, California, Accident Analysis and Prevention, 31:169-174). This study claimed to demonstrate that red light violations decreased by 42 percent in Oxnard after cameras were installed at nine intersections. Id.

Soon after release of this report, another — the first U.S. research on the effects of camera enforcement on intersection crashes — was conducted in Oxnard. That study, also by the Insurance Institute for Highway Safety, found that “injury crashes at intersections with traffic signals were reduced 29 percent after camera enforcement began; front-into-side collisions — the crash type that’s most closely associated with red light running — were reduced 32 percent overall, and front-into-side crashes involving injuries were reduced 68 percent, and; crashes declined throughout Oxnard even though only 11 of the city’s 125 intersections with traffic signals are equipped with cameras.” Redding and Kyrychenko, April 2001, Crash Reductions Associated with Red Light Camera Enforcement in Oxnard California, Insurance Institute for Highway Safety, hereafter 2001 Oxnard Crash Study.)

These studies have since been widely quoted and offered as evidence of the public safety benefits municipalities enjoy from automated red light camera enforcement. See, e.g.: Pagett, Disregard of traffic signals adds to traffic death toll (Jan. 18, 1999) Chicago Sun Times, page 2N; “The camera strategy is working. A study by the Insurance Institute for Highway Safety in Oxnard, Calif., showed that violations decreased by 42 percent after the cameras were installed in nine intersections. There was a similar decline of violators in intersections without cameras.”; Huddlestone, Bill would let cities use stoplight cameras (Dec. 18, 1998) San Antonio Express-News, page 1A, “A study by the Insurance Institute for Highway Safety estimates that Oxnard, Calif., reduced stoplight violations by 42 percent after cameras were used at nine intersections.”; Garston, Red-Light Cameras cut accidents and collisions, Insurance Institute study shows shift in driver behavior, (April 4, 2001) The Detroit News, “Cameras aimed at catching drivers who run red lights also are helping to prevent collisions and injuries, according to a study by the Insurance Institute for Highway Safety.”

However, recent controversy surrounding the methodology used by Institute researchers in the 2001 Oxnard Crash Study have cast doubt upon the validity of conclusion that automated enforcement systems increase traffic safety. Indeed, in at least one other study, researchers found an increase in accidents due to a rise in rear-end collisions associated with automated enforcement.

To read the entire critique go here: http://www.motorists.org/red-light-cameras/oxnard-critique

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