Atlantic blogger Eric Jaffe asks, “Can we stop pretending cars are greener than transit?” It’s a pointless question because no one really says that cars are greener than transit. On the other hand, claims that transit is greener than cars are vastly overblown.
Jeffe makes a few duffer mistakes that show he hasn’t thought this through. For example, he admits that it is a mistake (which many transit advocates make) to compare full buses with cars of average occupancy. He then proceeds to compare buses of average occupancy with cars with single occupants. But cars don’t average one occupant; the urban average is about 1.6 and the intercity average is about 2.4. While it is true, as many transit advocates point out, that putting one more person on a bus doesn’t significantly increase energy consumption, it is also true (and perhaps even more doable) that putting one more person in a car doesn’t significantly increase energy consumption.
Jaffe suggests that the reason why transit vehicle occupancy rates are low is because transit agencies “choose to design systems that favor coverage over capacity, knowing full well that will mean running some empty buses, because suburban or low-income residents need them.” In fact, “coverage over capacity” is a revenue strategy: agencies want to justify taxing wealthy suburbs, so they send buses and build trains to those suburbs even though most houses have three or more cars in their driveways. If we want to help low-income residents, it would be cheaper, greener, and greater help to them to simply give them used, but energy-efficient, cars.
Jaffe also admits that studies based on New York City are not representative of transit in the rest of the country. But he then accuses others of “cherry picking” data when they point to energy-inefficient transit in other cities. In fact, as page 14 of my paper on rail transit shows, there are only about six urban areas–New York, Atlanta, San Francisco-Oakland, Portland, Boston, and Chicago–where transit uses less energy and emits less greenhouse gases per passenger mile than a typical car.
Jaffe cites a Federal Transit Administration report claiming that the full life-cycle costs of transit are lower than driving. If he had gone to a more unbiased source, he would have learned just the opposite: the life-cycle costs of rail transit are more than twice the operating costs, while that of driving is only about 1.6 times the operating costs (whether costs are measured in energy or greenhouse gas emissions). If the goal is to reduce greenhouse gas emissions, it won’t be by getting people out of their cars and onto trains.
Ironically, it was an article in the Atlantic more than thirty years ago that blew up the fantasy that transit is some kind of solution to energy or pollution problems. University of California (Irvine) economist Charles Lave pointed out what he called the “law of large proportions”: “the biggest components matter most.” This means that, since 98 percent of urban motorized travel is by automobile, focusing on the other 2 percent is a complete waste.
Transit agencies that buy hybrid-electric buses, build rail lines, or do other things to be “green” are wasting taxpayers’ money. If we really want to be green, we need to focus on making the 98 percent greener, which we are already doing. Cars may not be greener than transit today, but they aren’t browner either. However, by 2025 or so, cars will be far more energy efficient, which transit is not likely to improve as much–indeed, transit uses far more energy per passenger mile today than it did 40 years ago. In all probability, in a little more than a decade, we won’t have to stop pretending that cars are greener because it will be true.