Red-light cameras don't reduce traffic accidents or improve public safety: analysis

Traffic Camera
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Red-light cameras don't reduce the number of traffic accidents or injuries at intersections where the devices are installed, according a new analysis by Case Western Reserve University.

Touted by supporters as a way increase public safety by ticketing drivers who continue through red lights, the cameras actually shift traffic patterns: More drivers tend to brake harder and more abruptly, increasing fender-benders and other so-called "non-angle" collisions.

"Once drivers knew about the cameras, they appeared to accept a higher accident risk from slamming on their brakes at yellow lights to avoid an expensive traffic citation—thereby decreasing safety for themselves and other drivers," said Justin Gallagher, an assistant professor of economics at Weatherhead School of Management at Case Western Reserve.

Gallagher is co-author of a paper posted to Social Science Research Network, commonly known as SSRN, based on an analysis of thousands of collisions over a 12-year span reported by the Texas Department of Transportation. Researchers focused on data while red-light cameras were operating and again after they were removed (by voter referendum) in Houston—and drew on similar data from Dallas, which still has its red-light camera program.

In Houston, the installation of the cameras led to 18 percent more non-angle , with an estimated 28 percent jump in these collisions in a combined Houston-Dallas data sample, researchers found.

While removing the cameras in Houston caused 26 percent more "angle" accidents—such as T-bone collisions, considered among the most dangerous—it's likely the cameras actually led to more accidents overall, since there are more non-angle accidents, researchers concluded.

"There is no reason to believe that there is a reduction in overall accidents thanks to red-light cameras," Gallagher said. "Our analysis does not support the case that the cameras improve public safety, which is one of the main justifications used by public officials and law enforcement."

More than 400 communities in the United States—including 36 of the largest 50 cities—have installed the devices, usually placed at busy intersections with a history of accidents. Yet some communities have removed the cameras, including Cleveland, where Case Western Reserve is located, and Houston.

The process of using the cameras to issue traffic citations—mailed to a vehicle's registered owner—has largely withstood legal challenges. But their use has also been heavily scrutinized as mere revenue generators, with most programs administered by out-of-state, for-profit contractors. Tens of millions of dollars were collected from drivers in Houston and Dallas during the years analyzed for the paper.

"There is clear evidence that installing a reduces the number of vehicles running a red light," Gallagher said, "but the predicted relationship between the number of vehicles running red lights and the total number of accidents is ambiguous—and certainly not compelling enough to justify some claims of proponents of these devices."

Data on the types of injuries incurring in these accidents (fatalities, incapacitating and non-incapacitating, and more minor) failed to provide a case the cameras increased the safety of intersections where they're installed, Gallagher said.

In 2015, more than 35,000 people died and 2.4 million were injured in nationally, according to the National Highway Traffic Safety Administration.

While the U.S. Department of Transportation recommends a set yellow-light caution length of 3 to 6 seconds, there is no uniformity among intersections.

Explore further

Traffic-light-controlled intersections found to attract fatal accidents

More information: Justin Gallagher et al. Criminal Deterrence When There are Offsetting Risks: Traffic Cameras, Vehicular Accidents, and Public Safety, SSRN Electronic Journal (2017). DOI: 10.2139/ssrn.3078079
Journal information: Social Science Research

Citation: Red-light cameras don't reduce traffic accidents or improve public safety: analysis (2018, July 19) retrieved 21 August 2019 from
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Jul 19, 2018
In canada, specifically in Ontario, such tickets issued for speeding or intersection violations, or for evidential use in any law breaking scenario whatsoever, were all struck down. At least with regard to the police or official forces using such cameras on government properties designed for public access.

It's called 'remote observation without a warrant'. And it's illegal in the USA as well, in the vast number of locations.

One has to consider the angle used, in court, when attempting to get such camera activities shut down. It's illegally utilized as it is legally... inadmissible evidence. No warrant, no evidence.

Jul 19, 2018
This is nonsense. I believe some justice wrote somthing like "It is not the severity of the punishment but rather the certainty of getting caught that deters crime.
I personally have been more careful at camera enforced red lights.
As far as privacy there is not a word about it in the constitution. And even if there were, this is used for vehicles not people.

Jul 19, 2018
And even if there were, this is used for vehicles not people.

So will my car have to get a job to pay off the fine? Will it be sentenced to several years of hard labor if it can't? What if the car is less than a year old?/ It'd be just a baby and hardly culpable for its actions.

Jul 19, 2018
Thamks Barakn, you beat me to it and said it better them I could. This does bring up, who is liable for vehicular misadventures by robot-driven cars?

I don't know about where the rest of you live but in my county, legality doesn't really matter. The private companies providing the monitor systems and municipalities and local police all want a cut of the loot shaking down drivers.

After all, if rge POTUS doesn't have to obey the law, why should anyone?

Locally, for the red-light cameras. you do not go to court. Instead, the accused driver receives a notice in the mail to show up at the monitoring offices for an interview. In private office, the clerk handling your case shows you the printout photos of your offense. Tells you how much you need to pay and holds their hand out expecting you to give them a check for that amount.

- cont'd -

Jul 19, 2018
- cont'd -
We sat there as she denied ever running a red-light. Then the clerk showed us the photographs.

I must say those were very high quality. I still kick myself that I did not bribe the clerk for a set of them. Exquisite detail of my very blonde wife peering up at the signal lights. Driving a distinctive porsche-yellow Mach II Ford Mustang, cherry'd-up for street racing.

Momentarily stunned at being caught out. My wife gamely rallied, berating the clerk for entrapment. I think one of her feminist lawyer girlfriends must have briefed her to insist on a court date.

The whole point of the red-light monitors was to provide another source of income without clogging up an already jammed court system.

The clerk sighed and caved and dismissed the ticket. No sense pretending that she, as a tall, blonde Scott/Dane could ever be convicted and with me as witness. Tall White Anglo-Saxon Predator class. No way to expect any court not to dismiss in frustration.

Jul 20, 2018
Phoenix had them on all the highways through town for a few years but we voted them all out, finally. However, some cities still use them at intersections. They are a huge revenue source for some small cities and they will fight tooth and nail to keep them. Having lived in large metro areas my whole life, I have seen many instances as described where people, especially non Native Americans, slam on their brakes as soon as they see a yellow light. Also, they wont turn right on a red light even when its legal if a camera is present.

Jul 20, 2018
This study mirrors others done by legitimate, unbiased researchers. The cameras are almost entirely for-profit revenue devices, not safety programs. Involving for-profit ticket camera companies in any part of traffic enforcement essentially guarantees the real focus will be profits - NOT safety. Red light cameras should be illegal in every state, as they are in many already.

James C. Walker, National Motorists Association

Jul 20, 2018
When you run a red light, unless you're some kind of entitled young teenage driver who is really in a hurry (We were all one once), it's 90% because you misread the yellow or something else in traffic took your attention away from the light, like not running over someone jaywalking or a bike veering into your lane or something. Sometimes it's slippery and if you hit the breaks too fast you'll just slide into the middle of the intersection and block traffic, so you have to just roll with it. If you add to those incidences the fact that if you don't immediately slam on your breaks anyway that you 100% are getting a ticket then you're just adding stress rather than any kind of useful deterrent.

Some locals who regularly speed because they know the area may be forced to slow down a little, but non-locals who get caught won't learn and slow down because they will never go there twice

Jul 20, 2018
Adding 1 second to the yellow intervals almost always reduces the violation rates by 70% to 90%. The rea$on$ citie$ $eek to u$e $lightly too $hort yellow$ are obviou$, and tho$e rea$on$ $pecifically exclude $afety.
James C. Walker, National Motorists Association

Jul 20, 2018
@kbk - Canada has a law allowing the police to pull people over and blood test them on the side of the highway, or arrest them if they have their cell phone WITHIN ARM'S REACH in the care while they are driving too.

Jul 21, 2018
Years ago I did an illegal U turn on an empty side street. I then turned right on a yellow light in a crowded intersection. Unbenownst to me a cop had pulled out after me and had tried to speed his way through the intersection on a red light, causing at least one accident. He kept after me, rather than stop, and when he caught me about a mile up the road he asked "Did you see that accident back there?"

I did indeed officer. I saw you swing wide into oncoming traffic in my rearview mirror. But I never saw a ticket. Did you lose your job or something?

How many accidents are caused by physical pursuits and pullovers? What about the cost and effect of resources diverted for chasing down scofflaws? Are these included in this study?

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