Which uses less energy and emits less pollution: a train, a bus, or a car? Advocates of rail transportation rely on the public’s willingness to take for granted the assumption that trains–whether light rail, subways, or high-speed intercity rail–are the most energy-efficient and cleanest forms of transportation. But there is plenty of evidence that this is far from true.
Rail advocates often reason like this: the average car has 1.1 people in it. Compare the BTUs or carbon emissions per passenger mile with those from a full train, and the train wins hands down.
The problem with such hypothetical examples is that the numbers are always wrong. As a recent study from the University of California (Davis) notes, the load factors are critical.
