Traffic: Why We Drive the Way We Do

And the subtitle is "(and What It Says About Us)".  The author is Tom Vanderbilt and here is the Amazon link.  I wrote the following blurb for it:

"Everyone who drives–and many people who don’t–should read this book. It is a psychology book, a popular science book, and a how-to-save-your-life manual, all rolled into one. I found it gripping and fascinating from the very beginning to the very end."

It’s out in July and so far it is one of the best popular social science books of the year. 

I also liked the article on traffic — John Staddon’s "Distracting Miss Daisy" — in the latest Atlantic Monthly.  It had these two good sentences:

Paradoxically, almost every new sign put up in the U.S. probably makes drivers a little safer on the stretch of road it guards.  But collectively, the forests of signs along American roadways, and the multitude of rules to look out for, are quite deadly.


Here's a link to the Staddon article:

My favorite sentence is: "I’ve given several talks on traffic in the U.S. and have always found members of the audience to be highly skeptical that the U.K. traffic system could possibly be safer than the one on this side of the Atlantic."

Pulling from my experiences and my friends' experiences in India, one of the biggest factors leading to traffic problems in India is the concept of driving in lanes. There is no education or enforcement of that concept at all. Driving in any city in India is pretty much a free-for-all that leads many down the path of religion, since it can only be through divine providence that they could have survived any day.

After reading the Staddon article, it occurs to me that the UK also has a much lower murder rate along with a much simpler prohibition on handguns. If Staddon's conclusion is that we should change to the British system for traffic regulation, why shouldn't we change to the British system for handgun regulation? Same logic, right?

And what about the Canadians?

And if Staddon is right about psychological factors undercutting safety attempts, then it doesn't matter what signage system or traffic regulating system we use: we will get the same result. So why would he think the British system would be better in the US then?

here it is ...

The tone of many comments here and on the links is very defensive. Why?

Steven, it's rational and reasonable, but I'm skeptical. I would expect that people driving old inefficient clunkers would be the most price sensitive and drop out. Also, the supposed increase in inefficiency I noted is over the past year. That would take a lot of very efficient cars coming off the road in a very short time.

The consumers who cut back their mileage the most in response to the gas price increases are also the consumers who drive the most fuel-efficient cars.

The claim could also be made that vacation trips, which are more likely to have extra passengers, are being cut before commuting trips.

John, from the site you provided me, demand data:

It's not good for a comparison, but it still looks like the decrease is not as big as the 4+% decrease in driving.

Sorry for not looking at it more objectively, but I've spent too much time on the computer as it is (I'm recovering from surgery on my arm).

Ryan, a more simple and probably much better version:

P1: Driving skill is correlated with age.
P2: Income is correlated with age.

IQ is not a good variable to include here. For instance, the ratio of university students, which presumably have an above average IQ, owning their own car is much smaller than the average car ownership ratio in that age group.

Steven, I agree with you. This is an adverse selection problem.

Aaron wrote "I would expect that people driving old inefficient clunkers would be the most price sensitive and drop out."

This is possible in theory, but is contradicted by the data. Every study of demand for autos I am aware of that allows for an individual's demand for fuel efficiency to be correlated with her price sensitivity finds a positive correlation.

One of the interesting thoughts on the Atlantic peice is claiming a greener solution for traffic is to make it more fluid (maybe decrease the stop signs, switch to one-way roads, etc). However, when you implement something like this, it will be a good solution for the drivers, but the pedestrians will be left out. The stop signs, obstructive parallel parking, and narrow two lane/two way streets are extremely inefficient, but they set up for a safer, more enjoyable pedestrian environment. So, making a greener and more efficient roadway might paradoxically make more drivers versus walkers which isn't very green at all.


You're right. Looking into the data more closely, it seems like a decline in "Conventional Finished Motor Gasoline" was overwhelmed by an increase in "Reformulated Finished Motor Gasoline." Perhaps it's due to additional ethanol mandates? Ethanol and 10% ethanol reformulated and oxygenated gasoline is less efficient per volume than gasoline. Hence an increase in the amount of ethanol used would indeed cause more gallons of gasoline (but not crude oil).


Wouldn't fuel efficiency drop if people cut down on their long distance driving more than on their local trips? The mix of high-mileage and low-mileage driving shifts so that a higher percentage of driving is inefficient.

More generally, you still have to go to work - very low-mileage driving in traffic jams, etc. - but might find more places within walking business for shopping, movies, etc., again changing the mix unfavorably.

Oh, and population growth combined with lack of infrastructure development is certainly a contributor.

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