Some smart-growth advocates argue that, even though housing costs more in cities than in suburbs, transportation costs in cities are so much lower that the total cost of housing plus transportation is lower. The problem with these claims is that they are based on average transportation costs.
As Steve Polzin, a transportation researcher from the University of South Florida, points out, low-income people spend a lot less on transportation than high-income people. He estimates the people in the top 20 percent spend five or six times as much on driving as people in the bottom 20 percent.
While wealthier people do drive more than low-income people, they don’t drive five or six times as much. Instead, much of the difference in expenditures “lies in the very meaningful differences between new car ownership and the reality that much of America isn’t driving new cars with high depreciation levels.” In other words, only a few people actually buy cars new and then replace them as soon as they’ve paid them off (which is the assumption that AAA makes in its annual cost-of-driving survey).