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Do Traffic Cameras Really Make Streets Safer?

They are despised by drivers and many lawmakers.

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I opened the mail one day last fall and found an envelope from the D.C. government charging me $100 for driving too fast on K Street on a Sunday afternoon a couple of weeks before. You go through little stages in those situations: First, disbelief -- “Surely we weren’t doing that.” Then, anger -- “Can’t the District of Columbia find a better way to pay its bills?” And finally, a fear of having blundered into a rigged game. Maybe we were going 39 miles an hour in a 25-mph zone, as alleged, but 25 is a suspiciously low limit for a spot just off a freeway. Is the whole point to make a little extra money off unsuspecting motorists? If so, the only practical way to enforce that kind of rule is with cameras, which is exactly how it’s done in D.C.

If this is the way they are going to use technology, you may be tempted to say, perhaps we’d all be better off if they took the cameras out. But would we? Let’s stop and think about it for a minute.

They’ve been thinking about it a lot in Iowa, where an angry and long-running fight is taking place between cities that consider traffic cameras an essential component of safety and conservative state legislators who see them as one more scheme for fleecing taxpayers. Both sides accuse the opposition of playing Big Brother. But they have wildly different ideas about just who or what Big Brother is. To the anti-camera Republicans in the legislature, Big Brother is the cities that have installed the machines to snoop on motorists. To the cities, Big Brother is an insensitive state government trampling on local rights.

Iowa began using the cameras in large numbers shortly after they were introduced into this country in the early 1990s. There are currently more than 75 of them in eight Iowa cities, placed strategically to photograph drivers going too fast or running red lights. In a typical year, the fines from these violations bring the cities about $12 million, which is their net take after they pay the private companies that install and maintain the machines.

The cities insist they are saving lives, as well as easing some of their budget problems. But the Iowa Department of Transportation has never liked the cameras, especially because a fair number are on state-maintained highways. In 2015, the agency ordered nine cameras shut down and three others moved off state property. The city of Cedar Rapids went to court to block the order. The initial rulings went the city’s way, but in April of last year a state judge told the city the cameras had to be dismantled. That meant a potential loss of several million dollars a year. Cedar Rapids took the case to the state Supreme Court, where it awaits a decision.

Meanwhile, however, the anti-camera faction decided to fight it out in the legislature and possibly preempt the Supreme Court. The result was an old-fashioned battle of ideologies, which played out on the Senate floor in February. “Big Brother has stepped in again,” warned pro-camera Democrat Tony Bisignano. “I don’t think the state should dictate to communities how to enforce their public safety.”

“The cameras are a racket,” countered anti-camera Republican Brad Zaun. “The whole thing is about money.” He insisted the main beneficiaries are the companies, some of them foreign, that put the machines in place.

Zaun’s side had the votes. The Senate passed, 32-18, a ban on traffic cameras in the state after July 1. That sent the issue to the House, where a sizable centrist faction argued that the cameras should be legal, but subject to state regulation. In the end, the House refused to ban the cameras, but approved an amendment requiring cities to present evidence they are needed.

The same argument has been taking place in Ohio. In 2015, the Republican legislative majority undercut the use of traffic cameras throughout the state by passing a bill that required an officer to be present any time a violation was recorded. This amounted to an outright ban. No police force in the state could afford to have its personnel spending their days lounging by the roadside next to a machine and waiting for someone to break the law.

It was a clever move, and in 2017 the state Supreme Court ruled that it was a bit too clever -- it constituted a violation of local sovereignty. Dayton immediately 

put its installations back in place. Joe McNamara, an attorney for the city of Toledo, called the decision “a great victory for home rule and local democracy.”

The argument isn’t over yet in Ohio. House Republican Rep. Bill Seitz has introduced legislation that would allow the cameras to remain in place but reduce each city’s share of state aid by the amount of money its cameras bring in every year. This too would be equivalent to putting the whole process out of business. In addition, anti-camera activists launched an effort to get a measure on this November’s ballot that would reinstate the officer-must-be-present rule. In late March, the House passed Seitz’s bill over the cities’ militant opposition. Given the judicial history on this issue, it seems unlikely that the bill could stand up in court. It will also require approval by the state Senate.

All of this, however, begs the fundamental question: Do traffic cameras actually save lives, or are they just a thinly disguised revenue scheme? A fair amount of evidence exists on this point, if the combatants are in a mood to listen to it.

Currently, about half the states have traffic enforcement cameras of some sort. Ten states ban them altogether. There are red-light cameras in more than 420 communities and speed cameras in more than 140. Citizens tend to trust red-light enforcement more than they do speed enforcement; one survey found 62 percent support for using photography to trap red-light runners.

Most of the statistics on these cameras come from the Insurance Institute for Highway Safety, which doesn’t disguise its support for camera enforcement, but doesn’t seem to have an incentive other than saving money for its members by cutting down on accidents. If the cameras didn’t make driving safer, the IIHS would have every reason to say so. What it says is the opposite. As of 2016, the IIHS was reporting that in some years red-light running had caused nearly 800 fatalities nationally. Most of the people killed were pedestrians or passengers, not the scofflaw drivers. Cameras had reduced the number of fatal crashes at photographed intersections by 21 percent. Turning the cameras off had caused the number of fatal crashes to spike by 30 percent.

The data on speed cameras is less comprehensive, but it points in the same direction. A seven-year study in Montgomery County, Md., completed in 2015, reported that the presence of speed cameras reduced by nearly 60 percent the number of drivers traveling more than 10 miles per hour over the speed limit. The IIHS extrapolated that, if adopted nationwide, a speed control program similar to the one in Maryland had the potential to prevent thousands of fatalities and injuries in a single year.

It’s possible, although I think unfair, to dismiss the IIHS as a predictable cheerleader for camera enforcement. But a couple of academic studies over the past few years have come to similar conclusions. Both have focused on red-light cameras in Chicago. Research conducted in 2014 by a team from Texas A&M University reported that cameras led to a reduction of 15 percent in the number of “T-bone” crashes --  ones in which two vehicles hit each other at right angles. A subsequent study in 2017, conducted by Northwestern University, found a 19 percent decline in fatal right-angle crashes at intersections where cameras were present.

Both of these studies, as well as earlier ones, found that the cameras actually led to a slight increase in rear-end collisions, because drivers tended to stop suddenly when they feared being photographed. But because rear-enders are less lethal than right-angle collisions, the net result in deaths and injuries was positive.

The academic research does suggest some simple ways that camera enforcement can be made more effective. One is to make the yellow interval between red and green lights longer. Chicago was making the yellow transitions as short as 1.1 seconds. Stretching them out by even a half-second encourages drivers to stop and wait for the next sequence rather than rushing through. But this adjustment for safety has a price; the Northwestern team estimated that a longer yellow light could cost Chicago as much as $17 million a year as a result of fewer citations issued.

The bottom line is that traffic cameras are a nuisance, and sometimes even an injustice, but there is no credible way to deny that they reduce the overall number of fatal crashes on American roads. Jurisdictions that rip them out are adding significantly to the annual death toll.

Having read through some of the history on this, I’m inclined to think the opposition to traffic cameras is based in part on a misperception of whom they are there to help -- who the real customer is. When I get a ticket for driving 14 miles per hour over the speed limit, I may have reason to be angry. But the cameras aren’t there to make my life easier. They’re there to protect all the other drivers who are threatened by my failure to obey the law. When they work properly, they are a modest price to pay for more safety. That’s why, once I vented a little bit about getting cited for speeding, I calmly wrote a check for $100 and went on about my business.

Alan Ehrenhalt is a contributing editor for Governing. He served for 19 years as executive editor of Governing Magazine. He can be reached at
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