I’ve been trying to get at why we chose the transportation modes we do, and see that a finer scaled investigation is warranted. The finest scale possible is the personal, so here goes:

I drove to this Starbucks because its cold and a little wet and I haven’t biked much in the last few months.  This weekend was a testament to that when I failed my legs on an attempt at 2 miles.

Now that we’ve got the middle aged confessional out of the way, I though it would be worth it to explore the age, wealth, and purpose of biking and walking decisions. If I was to wrest the same confessional as above out of a hundred or even a thousand others, I still would have no impartial idea about why people bike or walk as little, or rarely, as much as they do. There is a pretty strong mother confessor flavor in this question, which leads people I’ve talked to to apologize for biking less, or overestimate the amount they bike. A lot of people look upon biking in moral terms, and see not biking as a matter of sloth. I have come to see biking as a rational decision, and one that the conditions do not call for in much of America

I revisited the National Household Travel Survey to get at the question “who bikes?” There’s a rich line of inquiry, if not publication, trying to answer the class and racial meanings of biking. The rich reputedly drive bikes more, because they have the surplus time. Whites reputedly drive bikes more than blacks, because they feel safer in public, especially on public roads where all it takes for someone to kill you, no-fault, is a casual twitch of their wrist. I ma still looking for data on the second question, but I have found some data on the first.


The rich do indeed take significantly longer bike trips than the poor at almost all ages. I ould even parse out recreational versus work trips, but that’s for a later post.


The story with bike trips per capita is more equal between rich and poor, even if the difference in trip length is significant. The poor are probably riding for utility, and ride as little as they have to. The rich, meanwhile, are more likely to be riding for exercise, and ride as much as they can. I will look at that in a later post, though I already have the data from the NHTS.

By the way, the definition of poor (<$10k income per person) is very poor indeed, with a population of about 18 million, even in depressed 2009. The definition of rich in this survey (>$100k / person) is not all that rich, with a total population of about 56 million. While it would be interesting to look at biking for the other 227 million, it would not be as striking as looking at the two extremes.

To keep things in the human scale, I looked at the same comparison for walk trips. Walking, as I have shown before, is much more prevalent than we typically think, but who is doing the walking?


Here we see that the poor take many more walk trips than the rich, early in life, but then take fewer later in life. I will look in a ted post as to whether this shift is to traffic or transit. I suspect transit. In old age, pr any age, it takes a certain amount of wealth to deal with car ownership. Only in places where traffic is truly the only option with the very poor use a car. This is why the poor avoid living in those places if they can.


The average walk trip distance is amazingly pretty equal throughout life for rich and poor, holding between 0.5 and 0.9 miles from 5 to 85. I do not know what is up with the spike in walk trip distances for poor people between 45-49, but that’s a later post.

Sounds like this post raised more questions than answers. Good.