http://www.jrtr.net/jrtr23/F22_Hirooka.html

Since much of the ongoing cost of any large infrastructure project is the cost of capital, if you don’t consider government subsidies for construction and possibly the provision of credit on relatively easy terms, you’re missing a big part of the financial picture. What’s the difference between a government subsidy and a loan at a rate of interest hardly above the inflation rate? You tell me. How about if you can remove capital costs from your balance sheet, report a “profit” as a result, and thus qualify for a subsidy proportional to that “profit? Well, then you use the subsidy payments to cover interest on the loan, right? Maybe even pay back some of the principal.

Don’t get me wrong — I love the train system here. I think it’s the way to go. But mass transit has always required subsidies, and probably always will.

just because there are some plausible mechanisms of action for sitting on a train to encourage more trains to run does not mean that the marginal energy use of sitting on a train is the same as the average energy use of sitting on a train.

Making the train fractionally heavier is trvial. Crowding is not so important, presumably its effect could be markedly reduced by sitting in the corner. As for the future transit planners, if they enlarge transit systems, so that there are more trains, this will not only reduce crowdnedness but also reduce waiting times for trains, encouraging trains to be fuller.

The figures compare all transit to all cars. Most cars get better mileage on the highway than on city streets, but hybrid cars like the Prius, and electric cars, get better mileage on city streets. Transit figures include both city street transit and longer range transit, such as commuter rail which competes with highway. Commuter rail tends to be more efficient than intracity transit, because it has higher loads, makes fewer stops, and often doesn’t run much at all outside of rush hour.

However, don’t forget the core point. We usually work from the assumption that transit is much more efficient than private cars, and the assertion that transit is a bit more efficient than cars on city streets and less efficient than cars on the highway does not alter the conclusion that this is a poor assumption.

If you prefer to ask a more specific question, “which is greener, a Prius or a city bus” many would be surprised to learn it is the Prius, by a good margin. (Leaving out the debate on the energy cost of making both of them.)

Coal is one of the dirtiest sources of power. It does CO2 but a whole lot more, and then has coal ash residue when done. Natural gas is CO2 and not too much else.

As for hydro and nukes — well, no direct air pollution, but many people feel hydro has destroyed valleys, ecosystems and species. And people are of course mixed on how clean nuclear power is — some think it is the riskiest and dirtiest power, others think it is the cleanest.

In terms of air pollution, coal is worst, diesel 2nd, gasoline 3rd, natural gas 4th, nuke and hydro much lower. It’s an open question if an electric train that gets half its power from coal and 20% from natural gas is cleaner than a diesel bus or gasoline car. By CO2, a bit cleaner but by other pollutants, not so clear.

If you intend to increase “efficiency” by getting rid of solo car drivers, wouldn’t you also want to get rid of any bus routes which average under 7 passengers or so?

Perhaps everyone should just sit at home.

Manhattan + the boroughs comprise only about 1/3 the population of the NY Metro Area.

NY Metro’s density is 2,744/sqmi.
LA Metro’s density is 2,665/sqmi.

http://en.wikipedia.org/wiki/New_York_metropolitan_area
http://en.wikipedia.org/wiki/Greater_Los_Angeles_Area