Tuesday, January 19, 2010

Capturing Poor Driving

The following was put to me recently: How would you go about researching which areas/cities have the worst drivers?

Here's my take, note that I'm not really answering the question, and I'm sure Justin can improve upon it in half the words in the comment section:

1. It's tough to capture bad driving because many things that we consider to constitute "bad driving" aren't captured in any sort of statistics. I've yet to see the state-by-state time series of "number of instances of cutting someone off."

2. Surveys wouldn't work; I'd expect a similar result to 70%-of-people-consider-themselves-better-than-average-drivers. People systematically underestimate the quality of drivers around them. I am Exhibit 1A for that one.

3. Bad driving outcomes could very well be a function of mixing different types of drivers. Let's assume we've got two types of drivers, aggressive and passive. A city with nothing but aggressive drivers may well have more reported accidents than a city with nothing but passive drivers, but a city with a mix of the two may have the most of all. To that end, quantifying the quality of driver is only useful insofar that you can define the relationship between a spectrum of drivers operating within a driving environment.

4. With regards to age, I will say that more younger drivers (read: first few years of driving) make for more dangerous driving situations, if only because experience matters. It's unclear to me at this point how the upper end of the age spectrum looks.

What else is there?

Here's a post from the summer on courteous driving.


Jeremy said...

Doesn't this depend on your definition of "bad driving"? I find the drivers here in Chicago, on average, to be worse than in my home state of California. I consider drivers here in Chicago to be bad not because there are necessarily more accidents, but because sharing a road with these drivers is supremely frustrating. The drivers here seem much more passive, and, as such, it takes longer to drive shorter distances. For example, it takes me nearly an hour to drive the 10 miles to my office (in the opposite direction of the traditional, suburbs to downtown commute) yet it took me only about 30 minutes to drive to my high school, which is about 20 miles from my home (with equal distances of non-highway driving and large portions of it "with" the commute), and the driving takes longer when running an errand 2 miles from my suburban office in the middle of the day than a further errand in my hometown.

While much of the extra time it takes to drive is, admittedly, due to the City of Chicago's policy to time lights so drivers cannot hit too many greens in a row (to slow traffic an prevent accidents), this inherent slowness is exacerbated by the passivity of the drivers. This passivity is evident in watching drivers take longer to perform acts than is necessary; witness the many times I have seen the first car make it through an intersection after a red light before the second car starts to creep forward, drivers nearly come to a stop (in the driving lane) before making a turn off of a major street, and often drive below the speed limit when the weather is (and has been) fine.

Aside from my personal frustration with the length of time simple errands and "short" commutes take, I think much of this passivity is due to an ignorance of safe driving techniques and a lack of attention paid to driving. It is not safe to sit at a green light, stop in the middle of the road to turn or drive significantly below the speed limit. Even if you are not speaking on your cell phone while driving, it is similarly unsafe to fiddle with the radio, check an email on your BlackBerry or reach to the backseat for the box of tissues. When someone is driving he or she should be focused solely on the road and nothing else. While passivity can usually lead to fewer accidents, it can often be the result of unsafe driving techniques.

Justin M Ross said...

I think the first question you would have to ask is why bad drivers would not just be distributed uniformly over space. Shouldn't the average level of driver skill you encounter be the same in all areas?

Some areas might differ in a few key elements (like age, as you point out, or blackberry saturation, as Jeremy points out). Weather might be another obvious complicating factor. After some of these controls, I would expect very little stable variation in driving talent.

Matt E. Ryan said...

Given different local norms, the consequences of having a heterogenous mix of drivers in one city, and relocation, there is sufficient reason to believe that there's variance among driving scenarios across cities.

Matt E. Ryan said...

Different local norms as it pertains to the training of drivers, that is.

rolub said...

"It's unclear to me at this point how the upper end of the age spectrum looks."

Really, Matt? Because just one old person driving 3 mph under the speed limit in the left lane and breaking while approaching the intersection with the right-of-way green light makes me want to shoot somebody.

Matt E. Ryan said...

Well, old folks drive less and closer to home as well...I'm not sure how the elasticities play out in the end. I'm a bit more sympathetic the idea that their density of bad driving is greater, though I'm still not completely onboard with that. (Part of that is due to the fact that you need old drivers with aggressive, Cleveland-rooting drivers to create a bad situation. A humorous as it may seem to us to imagine such a place, a town of all old drivers would probably have very few accidents, though the driving may be "bad." But even that might be a reach because all old drivers may accept their style of driving as the norm.) Depends how we measure it, I suppose.

On a somewhat related note, I'd be willing to bet they are in a higher number of minor accidents but a lower number of serious ones.