For several years now, Americans have been driving less, a trend that started before the financial crisis and has continued even as the economy recovered. After decades in which distance traveled by car per capita in the United States increased reliably year after year, the decline is good news. People who live where there is less traffic tend to be healthier. They are more physically active, they breathe cleaner air, and, of course, they’re less likely to be injured in an automobile collision. Cars are also a major source of carbon dioxide emissions, which contribute to global warming. Fortunately, the amount of gasoline burned per person in this country has fallen sharply, as shown in the graph above by Michael Sivak of the University of Michigan.
Part of this decline in fuel consumption is simply due to the fact that cars are becoming more efficient. Higher fuel-economy standards are among the Obama administration’s signature environmental policies, and high gas prices and the sluggish economy have led drivers to buy leaner cars.
More simply, though, people are burning less fuel because they are spending less time on the road. While the total number of vehicles and the total mileage traveled in the country have begun to increase slightly again, the population is growing, and the averages per person are declining. People are putting more miles on each car, but that seems to be because they have fewer vehicles and may be sharing them with family or colleagues.
There are many explanations for the decline in mileage per person. Older people are driving less as they retire, and younger people are driving less, too, which Richard Florida thinks is because having a car just isn’t cool anymore.
In any event, federal and local policymakers are going to have to do a better job of anticipating people’s changing driving habits. In the past, they’ve predicted that historical trends in driving would continue, a mistake that turned the government’s efforts to promote ethanol into a regulatory headache. Also, bad forecasts can encourage transportation departments to invest in roads and highways, but if the past few years are any indication, investment in public transit infrastructure is needed more urgently. As Fitch warned recently, reduced traffic will mean that agencies depending on tollbooths to help pay for new construction will have to deal with skepticism on Wall Street when they need a loan. Projects that rely on bus and train fares, by contrast, might look more appealing to bankers.