Transportation: what's safe, energy, efficient, and cheap? You may be surprised.

Travelers, like companies, like a good ROI - return on investment. When deciding between traveling by car, train, or plane, it turns out trains - and Amtrak in particular - have distinct advantages over alternatives when considering safety, efficiency, and pollution.

Using deaths per billion passenger miles, Amtrak ranks with airplanes as 13 times safer than autos. Getting more than twice as many passenger miles per gallon than planes, Amtrak also beats out cars with fewer than five passengers. And Amtrak is the eco-friendliest, spewing out 82% less pollution than planes, and 70% less than cars.

But Amtrak takes a little longer, 8% longer between New York and Boston, for example, and costs a little more: 25 cents per passenger mile vs. 19 for planes and between 18 and 36 for cars.

Government subsidizes planes 16 times more than it does Amtrak; autos 32 times more. That works out to $1 billion for Amtrak, $16 billion for the airlines, and $32 billion for cars. Like travelers, maybe the government should better familiarize itself with the concept of ROI.