Kevin Drum has posted a few interesting thoughts about the impact sustained high gas prices are likely to have on the suburbs.Here are a few reactions:(1) While he's right that jobs are now as likely to be in the suburbs as in center cities, I don't think this means that high gas prices won't lead to more centralization. Commutes are only one way in which people use their cars, and most car trips are for other purposes. The problem with suburban development as it exists in this country is not just that it keeps people far from work, but also that it makes them reliant on their cars for virtually everything they want to do -- going to the store, getting to the park, taking their kids to school, etc. Relocating to a suburb nearer to work would eliminate some miles traveled, but it would not fix the problem (this is particularly true for two-career families). Higher density and, perhaps more importantly, mixing of uses would increase the ability of both spouses to live near work as well as replace a number of non-commuting car trips with walking and biking trips.(2) It's true that, as Robert Bruegmann has argued, the suburbs are not a new phenomenon that suddenly appeared in the 1950s, but mass suburbanization is a new phenomenon. The auto-dependent sprawl that emerged as the dominant land-use pattern in the U.S. in the middle decades of the 20th century was simply not possible before car travel was affordable and convenient to the middle class (e.g., before the arrival of mass produced cars, cheap gas, and highways). People's desire for space was not something new, but the scale of the spreading out that occurred in this country, particularly after WWII, was unprecedented. Just as this spreading out depended on affordable automobile travel, making car travel dramatically more expensive undermines the viability of that mode of living. Increasing the cost of living in the suburbs by $1000-2000 per family member (as Drum hypothesizes) would put suburban living as it currently exists out of reach for an enormous number of American households, and this would have a dramatic impact on our metropolitan landscapes. (For a household of 4, this would mean $4000-8000 more per year in fuel costs, or -- for the median family -- more than 10% of already stretched and stagnant household incomes.)(3) Drum is right that people will resist massively higher densities, but this something of a straw man (Bruegmann sometimes makes the same mistake of treating sprawl as if it were just a matter of density). A great deal of our auto-dependence could be eliminated by mixing uses without huge increases in density. That said, higher density is inevitable and, as Bruegmann himself notes, was already happening even before the recent run-up in gas prices. But this does not mean that everyone has to give up their yards. Transit can be made to work even with densities that permit most people to live in detached single-family dwellings.