Passenger-Miles

Blog post
January 15, 2010, 9am PST

Every so often, one sees an article arguing that one mode of transportation is cheaper, more efficient, or less dangerous than another because it uses less energy/kills more people/costs more per passenger-mile. (1)

It seems to me, however, that per passenger-mile comparisions are flawed in one key respect: they assume that trips on any mode of transportation will involve the same mileage, so that if the average driver lives 20 miles from work, the average bus rider will also live 20 miles from work.

Michael Lewyn