Do Traffic Tickets Make Us Drive More Safely?

For “Ask an Economist” this week, I have an interesting question from Stephen P. about the effect of traffic ticketing on driving safety. He asks:

Do traffic tickets and associated fines really make us drive better? I’ve been ticketed about once every 5–7 years on average. I do notice that I am a better driver after each “occurance.”

Most of my violations are legit with a few that seemed totally bogus. Did you know you cannot cross a gore stripe? Do drivers know about the gore stripe? Officer Friendly actually told me it was aggressive driving.

So, do traffic tickets make us drive more safely? Let’s explore some economic reasoning that can help us understand why they do or don’t, and then take a look at the evidence.

How Traffic Tickets Could Help Safety

To begin, we should first analyze why traffic tickets may make things safer for drivers. An economic principle underlies why they might. In simple terms: incentives matter.

Economists assume that people are rational. That doesn’t mean economists like every decision people make on a personal level. It just means that people prefer to have more of the things they like and less of the things they don’t like.

One thing we can pretty safely say people like is money. By this I simply mean that if there was a button to make yourself magically richer at no cost to anyone else, almost everyone would push it.

Since people prefer more money to less money, people will engage in behaviors less if you make those behaviors more expensive. For example, if Apple increases the price of the new iPhone by $100 tomorrow, there will be some people who were previously on the fence about buying it who are no longer interested. As the cost of doing something goes up, people do less of that thing on average.

Let’s apply this principle to something like speeding. We like to speed because we prefer to get places faster. It’s something we desire. There is, of course, a risk to speeding. It makes accidents more severe and more frequent. It’s also not great for the life of a car. But some of the risk caused by speeding is imposed on other people (drivers and pedestrians, for example).

Unless people are perfectly altruistic, they’ll likely care less about this external risk than the other drivers and pedestrians themselves.

You might decide that this means speed should be limited, and perhaps government is how this is imposed.

How can the government accomplish this task of lowering speed? Well, they can make it illegal to go above a certain speed. Obviously, it’s impossible for governments to have a police officer follow every car and regulate its speed, so they do the next best thing—they impose fines on people who are caught speeding.

You can apply this to any sort of driving behavior you deem to be unsafe. What is the result? Well, because the probability that you might get fined goes up, this makes it more expensive to go faster than the law says, or to drive dangerously. Remember, when something gets more expensive, people do less of it, all else equal.

This application of economic logic brings us to a simple answer. If properly implemented and enforced, we can imagine tickets and fines resulting in a safer road. Incentives matter, so fines for unsafe driving would mean more safety.

But there’s more to the story.

Unintended Consequences

Making unsafe behavior more expensive should lead to less unsafe behavior, but it’s possible that policymakers may create a policy which leads to unintended consequences which lead to less safety.

To understand why, let’s consider the effect of speeding tickets again. If you’ve lived in one place long enough, you’ve probably discovered the places where officers hide out and monitor speed. For me, there’s an old cemetery down the road that police officers sit at because the speed limit changes from 45 to 30 suddenly. Similarly, the main street in town is often monitored.

These locations make sense, and we inherently understand why police officers choose them. What is the result of this?

I can imagine a few possibilities that will lead to more unsafe driving. Let’s say I have 10 minutes to get to an appointment, and the main route to get there has a frequent speed check. What will I do?

Well, one option is to make up for driving slow near the speed check by driving even faster before and after the speed check. It’s conceivable that my trying to make up for the lost time of the speed check will cause me to drive even more unsafely than if there were no speed check. If officers could police for speed in a way that stopped us from learning their usual spots, this wouldn’t be a concern. But, in reality, this is a possibility.

Alternatively, I could choose a route which is in theory a little bit slower than the main route because using these “backroads” will help me avoid the speed check. Unfortunately, this might mean zooming down residential streets—rather than a main route with crosswalks—where people are not used to looking out for cars.

These are just two examples of unintended negative incentives caused by these sorts of policies. Consider another example: red-light cameras.

Red-light cameras mean people are less likely to speed through red lights. However, risk-averse individuals may slam on their breaks at a yellow light for fear that the camera will catch them in the middle of the intersection when the light changes. (Note, this is a problem as long as drivers believe this is possible. It doesn’t matter if the technology actually takes a picture in this situation or not.)

We would expect fewer mid-intersection collisions, but more rear-endings, at an intersection. Granted, mid-intersection accidents tend to be more dangerous than getting rear-ended, but then we have other considerations like how much each type of accident changes in frequency. For instance, if there are 5 fewer mid-intersection collisions per year but 50 more rear-endings per year, is the intersection really “safer” just because the rear-endings are less dangerous?

So, with both speeding and red-light cameras, we have one theoretical effect which increases safety, and we have another theoretical effect which decreases safety. Which wins out?

It’s probably impossible to say with certainty, given all the limitations of research and the large spectrum of unintended consequences, but there is some historical research on this topic.

Traffic Enforcement and Safety

Most studies you can find report that enforcement of speeding and traffic tickets leads to improved safety outcomes. For example, economists Makowsky and Strattman find increased traffic tickets in Massachusetts resulted in fewer motor vehicle accidents and injuries.

Similarly, red-light cameras have exactly the effect we would expect. That is, there are fewer intersection accidents with red-light cameras, but there are more rear-end accidents. Which effect is larger in terms of numbers seems to depend on the study.

We should qualify these results with a few comments. First, just because a particular policy at a particular point in history led to some metric of improved safety doesn’t imply that any traffic safety policy in any context will improve traffic safety. Again, we have two potential theoretical forces working against one another, and at any given time one could dominate the other depending on context.

Second, safety is only one value we care about. We also care about fairness, for example. In a different paper, Makowsky and Strattman find that traffic tickets are targeted toward people from “out of town” due to their difficulty with contesting the tickets. The research also finds that a city’s frequency of issuing tickets seems to depend on budgetary concerns rather than safety concerns. This is only one of many possible concerns about ticket fairness, but the point remains that even if tickets do improve safety, we may be trading some other value off against safety.

On a similar note, “safer” does not immediately mean “better.” What if a new traffic law could decrease the number of traffic accidents by 5 each year, but the law also caused people to waste thousands of hours more in traffic every year? These sorts of costs defy easy quantification and make the upsides of traffic tickets much more salient than the downsides, an issue that brings to mind Bastiat’s That Which Is Seen and That Which Is Not Seen.

In summary, what’s the effect of traffic rules on safety? Theoretically, there are good economic reasons to think it could go either way. As far as our studies can tell, these rules have led to net improvements in safety in some places. But we should remember that safety is only one of a myriad of things we value, so it’s far from obvious that safer always means better.