Report: Houston Manipulated Study to Make Red Light Cameras Appear Safer - 02-02-2009
Documents show that Houston, Texas mayor and police manipulated a study to make it appear red light cameras reduced accidents.

..."Recall our own findings match what is reported in [this Tampa Tribune] article and in the public health study cited in the article," Stein wrote in a March 14 email to Houston Police Sergeant Michael Muench. "Tim and I have reviewed ten year's worth of studies on red light camera programs and the tentative evidence that those studies using the weakest designs are most likely to report a reduction in side impact collisions after the installation of red light cameras. More rigorous and appropriate research designs (like the one we use for the Houston program) fail to detect this reduction after the installation of red light cameras."

In light of this, Houston police began to push Stein to weaken his design to match techniques used in studies conducted by insurance industry researchers and others with an interest in promoting the use of photo enforcement. In an April 29 meeting with police, Stein agreed to reconsider his results...

(Full article)

Study from Rice University

Report: Red Light Cameras Increase Injuries and Insurance Rates - 03-12-2008
Report published in Florida Public Health Review journal finds red light cameras increase accidents and insurance industry profit.

...An analysis published last week in the journal of the Florida Public Health Association argues that, contrary to common assumptions, the use of red light cameras leads to increases in insurance rates and injury accidents. Researchers Barbara Langland-Orban, Etienne E. Pracht and John T. Large closely examined the most often cited studies of red light camera use and concluded that not all of them were equally reliable...

Orban found the independent VDOT, Ontario and Burkey-Obeng studies (view studies) followed proper scientific methods and were fully open in sharing the data upon which the conclusions were based. These studies concluded that red light cameras caused an increase in injuries and overall accidents.

"Cities and counties should... pursue engineering improvements to enhance intersection safety for all drivers and passengers," Orban's report concluded. "Proven engineering practices and countermeasures can reduce crashes and injuries due to red light running, as well as other causes of intersection crashes."

(Full article)

Study from Florida Public Health Review

A Detailed Investigation Of Crash Risk Reduction Resulting From Red Light Cameras - 7-2004
Report published by the Urban Transit Institute at North Carolina Agricultural & Technical State University

Prompted by criticism of the simplistic methods and small data sets used in many studies of red light cameras, we relate the occurrence of these crashes to the characteristics of signalized intersections, presence or absence of RLC, traffic, weather and other variables. Using a large data set, including 26 months before the introduction of RLCs, we analyze reported accidents occurring near 303 intersections over a 57-month period, for a total of 17,271 observations. Employing maximum likelihood estimation of Poisson regression models, we find that: The results do not support the view that red light cameras reduce crashes. Instead, we find that RLCs are associated with higher levels of many types and severity categories of crashes. An overall time trend during the study indicated that accidents are becoming less frequent, about 5 percent per year.

However, the intersections where RLCs were installed are not experiencing the same decrease. When analyzing total crashes, we find that RLCs have a statistically significant (p<0.001) and large (40% increase) effect on accident rates.

In addition, RLCs have a statistically significant, positive impact on rear-end accidents, sideswipes, and accidents involving cars turning left (traveling on the same roadway). The one type of accident found to experience a decrease at RLC sites are those involving a left turning car and a car traveling on a different roadway.

When accidents are broken down by severity, RLCs were found to have a statistically significant (p<0.001) and large effect (40-50% increase) on property damage only and possible injury crashes. There was a positive, but statistically insignificant estimated effect on severe (fatal, evident, and disabling) accidents.

Link to the full results of the study