It has less energy by volume, which makes it problematic for cars. There are CNG converted cars, but the tanks take up all the luggage space in the trunk. There's more places CNG or LNG tanks could be placed in large trucks.
So if you decreased consumption of diesel would it increase the gasoline supply?
Of course Obama will find some way to kill anything which reduces costs.
The obvious place to try it is locomotives. They are going to plug in a “gas tanker” between the engine and the freight cars.
http://online.wsj.com/article/SB10001424127887324539404578342540494619344.html