I want to add to my point earlier today about the need to differentiate between modal shifts that are happening as a result of the economy and modal shifts that are happening as a result of changing preferences. I think that my point is best illustrated visually:

These are images from photographer Hans Kemp’s masterful book of photography Bikes of Burden (I think this is fair use!) in which Kemp compiled 150 of these completely beautiful photographs of two-wheelers carrying large loads. I think that these are particularly powerful because they are so obviously an effect not just of infrastructure or culture or individual preferences but also just of income.

Kemp argues that you see these scenes because the roads are narrow and because the demand for truly fresh food makes small trips more desirable than larger trips by truck, but I don’t buy it. The prevalence of non-perishables throughout the book eliminates the freshness theory. On the narrow streets, I can’t think of a city in history which has had narrow streets and not been able to, if it so desired, put in an automobile infrastructure.

I think that the more important point is that Vietnam is still a relatively poor country and motorbikes are cheaper than cars or trucks. I don’t think it’s possible to argue that the man with the dogs or the pig carcass wouldn’t rather, all things being equal, have a larger vehicle. I imagine the same is true for the family. There’s good evidence that the switch from bicycles to motorbikes was driven by rising incomes and that rising incomes will, in fact, soon switch residents of Vietnam’s cities into cars. That is going to be something of a disaster for emissions, of course.

Environmentalists, then, need to be sure that we aren’t dependent on decreased purchasing power as our only mechanism for getting people out of their cars. It is truly a wonderful silver lining to see SmartBike and Zipcar, as well as plain old public transit, bikes and walking, getting more users as a result of the recession. We just need to be implementing the kinds of improvements in those services that will get people to stay once purchasing power begins rising again.