What is the best new technology to replace fossil fuels in transportation?

You are really asking a silly question. So many products are created by fossil fuels that we will not really reduce the demand. Foe example, I am willing to guess the electric cars, fuel cell cars, etc are using tires - A petroleum bi-product. One of my favorites, "I'm converting my vehicle to LPG" - Well one guess where that comes from... If you really want to get off the dependence of fossil fuels, you need to examine the big picture...

search in google.

Henry Ford's Model T was intended to run on ethanol made from this crop. American farmers were predominantly growing this crop during the 1800's. they used it to make paper, rope, canvas... INDUSTRIAL HEMP

There are various methods such as thermal conversion processes or microwaves among others to convert garbage, plastics, crop wastes and other waste products into oil and fuels. In the US alone, billions of tons of garbage are currently buried in the ground which could be converted into oil....enough to meet all of our needs and then some at competitive prices. There are also methods to produce methane fuels, butanol or hydrogen using modified strains of microbes or bacteria such as e. coli. Hydrogen can also be created from seawater. Some nanotechnology methods can produce fuels with no emissions and low cost. Some related links and info.... Garbage and wastes into oil... http://www.i-sis.org.uk/WPIO.php?printing=yes Anything organic into oil... http://www.wnd.com/index.php?fa=PAGE.view&pageId=72275 http://www.sciencedaily.com/releases/2007/12/071210103934.htm http://www.sciencedaily.com/releases/2009/03/090330111257.htm Bio-butanol to replace gasoline..... http://www.enn.com/business/article/42416 Blacklight power...... Blue energy..... http://www.sciencedaily.com/releases/2009/10/091029160119.htm Cleaner fuels and synthetic gasoline .... http://www.sciencedaily.com/releases/2010/03/100322121100.htm http://news.discovery.com/tech/synthetic-gasoline-for-150gallon-and-no-emissions.html

There aren't any yet. But I'm sure in 500 years when the oil runs out somebody will come up with a good idea.

Electric cars. They're blindingly efficient as far as motor to wheel (around 90% as opposed to 20% engine to wheel for gasoline) so they use the energy the have extremely well. They also are much easier to service than cars with internal combustion engines. The four main drawbacks are they are only as clean as the infrastructure power plants that power them; Charging with coal power means they are not very clean. The second is current battery technology only allows them to go ranges of about 300 miles. The third would be they take a long time to charge unless you use a 220V plug (the socket you plug your dryer into). Finally, they are pretty expensive and it mostly has to do with people's willingness to adopt this type of AFV.

Cybernetics. True telepresence is going to replace most business travel, self-driving vehicles are going to completely rewrite over-the-road fuel usage assumptions.