Check out WPRT, they make Natural Gas engines that can be dropped into trucks and buses that currently use Diesel engines.
Interesting. I do have a question though. Someone reputable was on CNBC and said that a conversion of an existing diesel truck costs $60K. Is this true?
I would also add that the trucking industry is highly cost competitive. If a 5% savings can be made via a change to natural gas, it will happen since the industry looks for cost savings like a hawk.
Keep in mind one of the lessons of Buffett. Trying to pick the winners is not easy. Picking the loosers is easy though. His example (from the book Snowball) was from the auto industry's birth when the tech boom was occurring. There were hundreds if not thousands of automobile companies. 3 survivied (Ford, Chevy, Dodge). Point being that picking the winners is hard. But those that shorted the horse did well since it was easy to see that was a looser.
Anyways, natural gas transportation would require an infrastructure to support it. Locomotives can do this easily. The auto industry will need it to be done via stations all over the US. The logical path is long haul trucking as a starting point. That has to occur first since the infrastructure can be created easily (more easily) since locations can be away from major cities so start up costs are lower (land costs ,etc). As that occurs, "sub locations" can be created as the industry expands.
EDIT: WPRT is priced with HUGE expectations baked in right now.