On Friday, the Chicago Tribune released the results of a study it commissioned on injury crashes and red light cameras, revealing that while right angle crash incidents have been reduced, rear-end crashes that resulted in injuries went up 22 percent. The results of the study throw cold water on the booster efforts of Mayor Rahm Emanuel's administration and raise questions about the use of red light cameras as a whole.

Chicago is the home of the nation's largest red light camera program and encompasses 350 cameras at a variety of the city's intersections. The red light camera program has been accused of mismanagement and embroiled the mayor's office in a $2 million bribery scandal. But recently, administrators trotted out a seemingly redeeming statistic: that the introduction of the cameras had created a 47 percent reduction in the rate of right angle, or “T-bone,” injury crashes.

The Chicago Tribune in response commissioned a scientific study by two well-regarded transportation researchers, who found that the statistics promoted by the mayor's office were misleading. According to the Tribune, the authors of the study found a statistically significant, but still smaller, reduction in angle and turning injury crashes by 15 percent, as well as “a statistically significant increase of 22 percent in rear-end injury collisions.” Overall, there was “a non-significant increase of 5 percent in the total number of injury crashes” that happened at intersections with red light cameras when comparing the injury crashes that occurred there before and after the cameras were present.

On a more granular level, the researchers found that there were no safety benefits from cameras that are installed at intersections where there have already been few crashes with injuries, and occasionally, there was evidence that red light cameras actually increased injury crashes at such intersections. "When intersections experiencing fewer than 4 injury crashes per year are considered, there is a significant increase in all crashes by 19 percent after the installation of RLCs," the Tribune study found.

The Tribune noted that the red light camera program has raised more than $500 million off of the $100 tickets since 2002. "That program needs to be stopped. It needs to be frozen to give us time to re-evaluate everything," Chicago Alderman Anthony Beale, 9th, chairman of the council Transportation Committee, told the Tribune. "This is just more proof that this entire program is strictly to generate revenue and always has been."

Back in July, investigative work by the Chicago Tribune revealed that at least 13,000 Chicago drivers were cited erroneously through the city's red light camera program.

Doubts about red light camera programs have been creeping into the consciousness of some of the formerly more fervent red light camera supporters in municipal governments. In 2013, Ars chronicled some of the more questionable cases of red light cameras in cities like Modesto, CA. Iowa City and Mississippi have both made the installation of red light cameras illegal. And as recently as November, red light camera company Redflex called North America a “low/no-growth market” due to revenue volatility and federal investigations.