USF study finds traffic cameras ineffective


The number of red light cameras in use at intersections across Tampa has more than doubled since 2011.

On Jan. 1, the Tampa Police Department (TPD) added 15 more traffic cameras, bringing the number of monitored intersections to nearly 20.

On its website, TPD cites the Insurance Institute for Highway Safety (IIHS) saying the “intersection safety program will be very important to the safety of our local road ways.”

However, an analysis recently published by three USF researchers found one of IIHS’s own studies may prove red light cameras ineffective at preventing traffic fatalities.

The analysis, published in “Health Behavior and Policy Review,” was conducted by USF Health professors Barbara Langland-Orban, Etienne Pracht and John Large. 

The group had already been examining red light camera studies since 2008 when it received a state grant to look for new sources of revenue for Florida’s trauma system. 

After analyzing a large number of comparative studies, the group realized the science behind the traffic safety program was absent.

“What the larger studies at the time showed was quite the opposite to what we all thought,” Pracht said. “These red light cameras are actually associated with higher risks of crashes, particularly rear-end collisions. People in the trauma system didn’t want to become dependent on something they were trying to prevent.”

In their most recent analysis, the group looked at the IIHS study conducted in 2011 that claimed red light cameras reduced the risk of fatal red light running crashes by 24 percent.

After looking at more than 99 U.S. cities, researchers from IIHS said their study showed that red light cameras saved 159 lives between 2004 and 2008. They also claimed 815 deaths could have been prevented if cameras were operational in all large U.S. cities during that time.

When the USF researchers began their independent analysis of the data, Pracht said they saw that Phoenix, Ariz. had an astronomically high rate of traffic fatalities during the time IIHS was conducting its study, accounting for more than half the variation in the IIHS study.

When USF researchers attempted to replicate the study leaving out Phoenix as an outlier, the numbers changed dramatically.

“All of a sudden we went from seeing the significant reduction in fatalities that IIHS claimed to seeing no significant change at all,” Pracht said. “Basically their study was a comparison of apples to oranges.”

The problem, researchers said, was in IIHS’s methodology. Many cities that installed red light cameras, like Phoenix, started out with a rate of traffic fatalities much higher than the average. USF researchers also pointed out that many of the cities in the control group started out with less than two fatalities a year.

“It’s very misleading,” Pracht said. “When you look at one group and see that they had an average of 10 or 11 fatalities that dropped to around eight or nine. … (Then) look at their control group who had less than two and see it hasn’t changed and therefore the cameras must be the thing that was effective.”

Pracht said the data collected by IIHS researchers, when interpreted correctly, actually showed there was no tangible benefit to using the technology.

Another issue many researchers have with red light cameras is the reduction of yellow light intervals.

An investigation by 10 News Tampa Bay found that, in 2013, the Florida Department of Transportation approved a rule change allowing for local municipalities to shorten the length of yellow lights.

According to the U.S. Department of Transportation and Federal Highway Administration, a one second increase in yellow light intervals decreases severe red light related crashes by 40 percent.

Intersections with red light cameras in Tampa were found to have yellow light intervals below the state’s four-second minimum at two intersections.

Pracht said his research into the efficacy of red light cameras over the years has lead him to believe that public officials have chosen to do what is most cost-effective instead of what is in the interest of public safety.

“The objective of these cameras is to generate revenue,” he said. “If it was a safety issue why would they decrease yellow light intervals, which have been shown to cause more accidents? In order to give out more tickets. There are simple solutions, we just aren’t doing them.”