Ok, well trains do alot the way it is, not every supermarket, gas station, etc is conviently located right off the tracks... Trucks need to bring it locally, tell that to the millions of drivers, yea it costs 1200 bucks to fill each of them up. Lets just tear down the highways and have every one take a train to visit relatives, not logical. Its cheaper to Run food in a reefer then it would be to get it all on the train, would cost the supplier a $hit ton more to get it on a train.... Railroads are becoming extinct, Diesel technology in Big rigs a is getting more and more advanced, and can only get so fuel efficient, The trucking companies are setting the governers lower to about 55-60 mph now to get the best fuel efficiency.
*Note that I said "long haul drivers" which in my eyes is someone that is on the road for days possibly weeks at a time running state to state, not a 12-14hr shift(day run).
*Your bit on trains being extinct and not efficent, read your facts bud. CSX has been around for many many years and going strong. CSX runs through 23 states(but what about the other 25 main land states????) and have spent 1 billion dollars to upgrade thier fleet to reduce fuel coonsumption and air pollutant's. CSX have increased fuel efficiency 80% since 1980, seems pretty damn good IMO.
http://www.csx.com/share/media/media/docs/GenSet_release-REF24333.pdf
*^^^^Note that the GenSet Loco will be used for switching loads, thats actually where the most energy is needed since there constantly throttling up and down.
*Also most trains nowadays have diesel engines but thats not what actually propels the train, they used the d-engine to drive generators turning that energy into electricity which can be stored and used.