What’s a City For?

This post originally appeared in  Symposium Magazine.

What’s a city for? We say a city exists to increase accessibility, to enable people to reach things they care about. The thing they care about reaching most, outside of their immediate family, is the workplace.

There are 8,760 hours in the year. In the United States, those who work full-time do so for about 2,000 hours (40 hours a week for about 50 weeks a year, discounting vacation and holidays). Fewer than half the people work (while the rest are children, retired, stay-at-home parents, unemployed, or independently wealthy) so the average person works about 800 hours. This means about 9 percent of urban time is used for work.

Average work travel for those who work runs less than an hour round trip, say, about 240 hours per year. Less than a third of that is due to congestion delay, 80 hours. That’s about 0.9 percent of urban time. What all this rough arithmetic says is that transportation planning focusing on work trip congestion is concerned with only a small share of urban life.

To be sure, this remains meaningful because the ease of the work trip bears on choices of housing and jobs. Furthermore, the peaking of work trips is the time of the worst congestion – the point when people see the transportation system “failing.” But most people spend most of their time doing things other than being “stuck in traffic,” and we should consider that as well.

Excerpted and adapted from The Transportation Experience: Second Edition, by William Garrison and David Levinson (Oxford University Press, 2014)