A gallon of diesel fuel cost an average of $3.97 last year, according to federal statistics. The equivalent amount of energy in natural gas cost 48 cents at industrial prices.
Berkshire’s BNSF Railway to Test Switch to Natural Gas
http://online.wsj.com/article/SB10001424127887324539404578342540494619344.html
To get around the subscription requirement for some Wall Street Journal articles, you can search for the title and click the link from the search engine.
First link at the above search.
Does the diesel price ($3.97) include road taxes, which wouldn't apply to railroads? Thought about that after I'd posted.