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.
In other words, "Because no one rides public transit, we should not make efforts to improve the utility of said public transit." People don't ride buses largely because they're often not complemented by a decent train system, or because it's too much of a pain in the ass due to shitty design (I'm looking at you MARTA). In the US, I've used the Chicago bus system to good effect, and in Fukuoka, Japan, we never even got on the train because their bus system is well designed and efficient (and inexpensive). If you build it (correctly), they will come. 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.
Whereas road building has none of those ill effects, I'm sure. Not to mention the often overlooked secondary effects of car culture, namely, sprawl, which begets deforestation, more construction of energy inefficient and likewise environmentally damaging home and strip mall 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.
Again, "People didn't seem to change their minds about driving when we put in this crappy bus line from one place to one other place, so why should we put in more?" * Powering buses with hybrid-electric motors, biofuels, and—where it comes from nonfossil fuel sources—electricity;
* Concentrating bus service on heavily used routes and using smaller buses during offpeak periods and in areas with low demand for transit service;
Good ideas, and should be included in any new transit planning. * Encouraging people to purchase more fuel-efficient cars. Getting 1 percent of commuters to switch to hybrid-electric cars will cost less and do more to save energy than getting 1 percent to switch to public transit.
Reasonable, but neglects secondary effects, and also probably not as easy as it sounds. Market effects have encouraged hybrid ownership, but far less than one would expect. * Building new roads, using variable toll systems, and coordinating traffic signals to relieve the highway congestion that wastes nearly 3 billion gallons of fuel each year;
Of course, we need more roads. I'm ok with variable toll systems, though I think there are issues to be worked out. I'm very curious to see how Atlanta's highway on-ramp traffic light system will fare once it's operational. I've read nothing about it, but they've been installing the signals for months and months now. I'll reserve judgement until I know more. If oil is truly scarce, rising prices will lead people to buy more fuel-efficient cars. But states and locales that want to save even more energy and reduce greenhouse gas emissions will find the above alternatives far superior to rail transit. RE: Does Rail Transit Save Energy or Reduce Greenhouse Gas Emissions? | 
