Death by congestion – should we care?

We live about 700,000 hours.

If we believe the Texas A&M Transportation Institute (and the number seems plausible) every year, each rush hour commuter loses 42 hours  per year to congestion.  Keep in mind each rush hour commuter is commuting about 167-250 hours per year, so this is like a 17%-25% congestion tax, not that high all things considered, similar to income tax. Whatever you think about the quality of the measure, or its measurement, this is probably ballpark.

There are about 325 million US residents.

If we lose 42 hours per year, for 80 years, each person in this example loses 3360 hours over their 80 year lifetime to congestion. 3360 hours is about 140 days (~4.5 months).

To compare this, we may want to convert to DALYs – Disability Adjusted Life Year.  42 hours * 100,000 people = 4.2 million person hours per year per 100,000 people. This is 6 full lives per year per 100,000. Across the US, this 6*325 million/100,000 = 19500. Given that the “average” death by car probably occurs near the midpoint of life, and congestion delay also is spread out across life, not just at birth, we could double this for comparability with car deaths. In an earlier post I reported on “Death by Car: Are you more likely to die from a crash or breathing its toxic emissions?“. I posted the following


In the US, according to the Global Burden of Disease Study (Data Link), for 2010, for men+women:
road injury + other transport injury total air pollution
Deaths: 15 36
DALY: 797 624
Years of life lost: 653 565

Thus, our putative 6 (or 12) lives per year per 100,000 lost to congestion is below the lives lost to road injury and overall air pollution (of which a large fraction (~25%) is likely transportation related). 

Keep in mind that most people don’t work (even among working age people, the employment ratio is only 59%), and of those that do work, many don’t work in rush hour, so this is definitely an exaggerated,  upper end estimate. Of course non-workers also suffer congestion, just to a lesser extent.

On the other hand, there is time lost during “freeflow” travel too — any time you stop at a red light or stop sign when there is no one else there, that is unnecessary delay, that is probably not accounted for the above estimate. This suggests delay may be a bit higher, even if not due to other cars on the same road as you, but due to potential cars on roads crossing your path. That is not enough to outweigh the overestimate part.

Also some of the pollution death is related to emissions of cars that are stuck in traffic. Do we attribute that to congestion or to travel?

Moreover, this brief analysis assumes people can do nothing else when traveling, which is a huge overestimate, since time passes, but is not really fully wasted, even if we don’t text, we still listen to music or think or rest, and many people actually like commuting, to a point.

So, in short, our response to congestion should be of course to price the roads, and manage traffic better, and automation technology will help if not entirely eliminate the problem, but if we don’t like those responses, the next best response is not widening roads. It should be “meh,” we have bigger fish to fry, like the actual deaths our transportation system causes (which will also be reduced with technology, but not entirely eliminated either).


See also: Hauer, Ezra (1994):Can one estimate the value of life or is it better to be dead than stuck in traffic?

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