possibly noteworthy wrote:

Far from protecting the environment, most rail transit lines use more energy per passenger mile, and many generate more greenhouse gases, than the average passenger automobile. Rail transit provides no guarantee that a city will save energy or meet greenhouse gas targets.

While most rail transit uses less energy than buses, rail transit does not operate in a vacuum: transit agencies supplement it with extensive feeder bus operations. Those feeder buses tend to have low ridership, so they have high energy costs and greenhouse gas emissions per passenger mile. The result is that, when new rail transit lines open, the transit systems as a whole can end up consuming more energy, per passenger mile, than they did before.

Even where rail transit operations save a little energy, the construction of rail transit lines consumes huge amounts of energy and emits large volumes of greenhouse gases. In most cases, many decades of energy savings would be needed to repay the energy cost of construction.

Rail transit attempts to improve the environment by changing people’s behavior so that they drive less. Such behavioral efforts have been far less successful than technical solutions to toxic air pollution and other environmental problems associated with automobiles.

sigh, this is a classic example of trying to solve the symptom and not the problem. The problem isn't that mass transit (or automotive transit) is what needs to "go green". Trying to engineer green vehicles is the WORST end of the value chain because it's the most complex to engineer and the most price sensitive to the customer (since it's directly consumer oriented, rather than systemic). Cars only account for about 25% of greenhouse gases and energy consumption in the US.

The smart approach to this would be to apply development at the electric power system, particularly for commercial/industrial customers, who are the lions share of greenhouse gas emitters and energy consumers. There's a variety of means to achieve this and I firmly believe that there should be a competitive market with incentives around development. This would propagate multiple technologies that would compete on efficiency for a variety of situations. Use hydro and wind on the coasts. Solar in the south. Nuke in the midwest.

Once that gets sorted out, most of the engineering problems will be solved and there will be enough development time to bring forth more mature solutions to something like mass transit. The cost curves will be more attractive. There will also be a more readily available infrastructure direction. So if it's cheap electricity, then we can focus on making cheap electric cars and distribution for it. If it's something else, then it will be directionally clearer.

Unfortunately the political hot button is what can get an individual consumer engaged. That's who votes. With their ballots and wallets. That's great if it does motivate change and innovation, but a sensible policy could do the same thing and much more intelligently.

RE: Does Rail Transit Save Energy or Reduce Greenhouse Gas Emissions?