> In summary, inter-city trains are not the most efficient way to
> travel today, using only a passenger mile per BTU calculation.
>
> KGN
I think this conclusion is a bit misleading because it involves comparing apples to oranges. Cars are usually used for short-distance commute, so comparing them to intercity trains that - outside the NE corridor run largely empty is really comparing apples to oranges. A better way is to compare cars to commuter rail, which is available in the table you cited an which I reproduced below. It shows that commuter rail uses almost half the energy used by "personal trucks" aka SUVs, and about 75% of energy consumed by automobiles. I may also add that this inequality would further increase if we had better commuter rail system (e.g. higher usage, electric instead of diesel locomotives, etc. ).
As you correctly observed, comparing intercity rail to air travel should also be adjusted for the load factor, but also the distance traveled. A disproportional share of energy consumed by the plane is at the takeoff, and once the thing is in the air, the farther it flies the more energy-efficient it is. So I would say that relationship between rail and air travel is non-linear: trains are probably more efficient than planes in short-to-medium distance intercity travel (e.g. under 200 miles), but become more efficient as the distance increases.
Wojtek
(Btu per
passenger-mile) Automobiles 3,581 Personal trucks 4,057 Motorcycles 2,274 Demand response 13,642 Vanpool 1,362 Buses a Transit 4,127 Intercityb a Schoolb a Air a Certificated routec 3,703 General aviation a Recreational boats a Rail 3,370 Intercityd 4,830 Transite 3,268 Commuter 2,714