I see a lot of green solutions out there. I've found if they sound to good to be true they probably are. Especially if they contain all the good high concept buzz words. The idea below contains the following: Hydrogen, Photovoltaic, Maglev, carbon sequestration. To name a few. Look at the site and notice how there are no specifics on how anything works, and why are there technical drawings on notebook paper?

http://www.hydrogensuperhighway.com/

Where do I begin...  first the big ones.

Why hydrogen to run the train? maglev runs on electricity. Making hydrogen by breaking down water with electricity is very inefficient.

The solar panels are partially shaded by the tracks, and in most situations there position would be far from ideal. Where does the power go and how is it used? it goes to a substation where the electricity is used to take water and electrolyze it to produce hydrogen, that is used to run a generator to make electricity. or in anther version. The electricity is used to electrolyze water into hydrogen and Oxygen, to put in a fuel cell to make electricity, to capture the water vapor to distill into clean water. Wtf? Water and electricity in and a lot less electricity and some distilled water out. seems like a huge waste of energy to get some distilled water. Reverse osmosis is a lot cheaper and more efficient, than building a million and half dollar energy waster... every 4 miles.

Maglev requires a certain amount of area to create enough lift. Those small sleeves are not enough. If the train is running on a permanent magnet rail, which is what it looks like they are saying. it will not float at low speeds. AND the rail need to be aluminum. a steel tube will cancel out the magnetic forces.  So from a physics standpoint the proposal is lacking. It's hard to beat the price and efficiency of steel wheels on steel track.  Another problem is that when one starts to use small trains the size of large buses, one loses the economy of scale that one get's with a big train. The loss of drag due to maglev is cancelled out by the use of individual cars. Each one has it's own wind resistance to deal with, there is no slip-streaming of the cars. If the cars are making a lot of stops it may not get into maglev at all, since permanent magnet maglev only works at high speeds.

We have learned that growing plants for carbon sequestration only works for the first season. researchers using the old Biosphere project as a laboratory have found that plant vegetation on bare land only absorbs CO2 the first growing season. After that the absorption of CO2 from new growth balances out with the production of CO2 from fallen leaves and soil processes.  There is a slight bit of carbon sequestration from the increase in live vegetation, but once it dies it is cancelled out. That is why the Biosphere project failed. They did not realize that the bulk of the oxygen on the planet is make by the oceans. so although it would be nice to have beautiful landscaped train rights of way, it's not helping the CO2 problem.

The proposal claims to solve a host of other problems as well.  The tracks would deliver water, waste, electricity, and Internet. I wonder if they want to put cable in there as well. Do we need our waste water overhead? how does it effect drought and famine? and claims like "Ultimately, we are creating a massive functional upgrade to the efficiency of the United States public infrastructure as a whole by implementing a nested domain address system for a National Public Transit Network." what does that mean? isn't that used to distribute packets of information on the internet. People are not electrons and are not so easily managed.

Then sprinkle the whole thing with highly technical terms that are inappropriately used as well as global problems not solved by this proposal. make sure that you have covered the  important minutiae without fleshing out the entire engineering. It's sort of like designing the tray tables when you haven't figured out the plane yet.

I wish them luck.....