NCPA - National Center for Policy Analysis

Which Is Better for the Environment: Transit or Roads?

July 13, 2012

Policymakers have gone to extraordinary efforts to make mass-transit rail a realistic mode of transportation. In addition to enormous subsidies for light rail throughout the country's metro areas, they also encourage rail-conscious city planning and engage in a public relations campaign on its behalf, says Randal O'Toole, a senior fellow with the Cato Institute.

Still, rail lags far behind autos in its convenience and use, serving dramatically fewer people every year than the nation's cars. And while the environmental lobby decries this fact, in-depth analysis shows that it may be for the benefit of everyone. This is first true when considering rail's environmental impact in terms of energy consumption.

  • Energy consumption by autos and transit can best be compared using common units such as British Thermal Units (BTUs) per passenger mile.
  • According to the most recent report from the Department of Energy, in 2009 the average passenger car on the road used about 3,500 BTUs per passenger mile.
  • Nationwide, light rail uses approximately the same amount of energy, but this includes the anomalous New York rail system that, because of exceptional volume, is more efficient.
  • Most cities' rail systems are grossly less efficient than cars: in 2009, Baltimore's used around 6,000 BTUs per passenger mile; Cleveland's more than 8,000; and Miami's 5,400.

In terms of emissions and pollution, cars also have the advantage.

  • For petroleum-powered vehicles, greenhouse gas emissions are proportional to fuel consumption.
  • For electric-powered vehicles, however, greenhouse gas emissions depend on the source of electricity.
  • This means that for light rail, its emissions must be measured in terms of the amount of electricity consumed and the method by which this electricity was produced.
  • Since most states get most of their electricity from burning coal or other fossil fuels, electric-powered transit is no greener than driving and often much less green.

Finally, the cost of light rail is much greater than the cost of individual vehicles.

  • According to the Bureau of Economic Analysis, the total cost of driving cars for Americans in 2010 amounted to approximately $975 billion.
  • Taking into account the miles driven and number of passengers, the cost of driving per passenger mile is about 22 cents.
  • Yet the total cost of light rail, including subsidies, is approximately 98 cents per passenger mile.

Source: Randal O'Toole, "Which Is Better for the Environment: Transit or Roads?" National Center for Policy Analysis, July 2012.

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