Last month I did this trip, Amtrak was the most expensive per mile and most memorable leg and that was at the super cheep winter sale price
elta Air Lines JFK-DEN $103.90 (6¢ per mile) - in all my travels at least last year when I started keeping track was cheapest Amtrak leg was 8¢ per mile
Amtrak California Zephyr DEN-SLC $60 (11¢ per mile)
JetBlue Airways SLC-JFK $152.80 (8¢)
The argument of value per dollar comes to mind here. Sure, airlines *might* be less per $0.01 spent (not really when you equate the true cost as an American tax payer, which is a mirage of many men behind many curtains,) but their only real value is the time in travel between point A and B. If time is not so preciously and vastly hoarded, I still think other forms of transit win hands-down on the airline fleecing scheme.
True, Amtrak travel is more relaxing. But, for much of the country, it's simply not a viable option. Especially when you're considering long-distance trips and you have to spend time at the destination. For example, to get from MSP to BOI (a trip I'm actually taking this summer,) it costs $265 each way and takes 43 hours out, 47 hours back (including 8-10 hours on a bus each way, and an overnight transfer on the way out and an 11-hour transfer ending at 1:30 AM on the way back.) On Southwest, it's $207 each way and takes 5 hours out, 6 hours back, with both transfers at reasonable hours. Guess which one I'm taking?
Amtrak's advantage is in shorter routes (or shorter trips). They usually wind up being no more than the airlines (especially after fees) and can be close to as fast, if not faster, than flying when considering time spent in security at the airport. But trains only have an advantage on long-distance routers when they are cheaper than equivalent flights, or getting to smaller towns that aren't well-served by the airlines. (Even then, it may make sense to fly to the larger airport and take the train from there.)
Plus, while it may be more expensive, when considering the respective subsidies, to fly, the cost to fly is a "sunk cost" for the consumer. The only part I care about is the additional out of pocket cost for traveling.
While you may not care about speed, many people do. They don't want to spend their vacation days taking a train out to where they want to wind up, especially if their main purpose is to be at the destination. The journey on the airlines may not be as enjoyable as it is on Amtrak, but many Americans just want the journey to be done ASAP. Trains can't offer that on longer routes.
Airlines can do awful things on non-ecompetitive routes where there is no real competition. OTOH on the major trunks the airlines have very little pricing freedom unless they can carry a whole bunch along. Repeatedly attempts to raise prices are thwarted because a Southwest or a JetBlue does not tag along. But the general better management of inventory across the industry is here to stay so the airlines these days have more upward pricing mobility than they had in the past. But still it has to be a collective act. A single airline can go its own way only at its own peril.
That's why there's really no difference between domestic flights now. All airlines, low-cost or not, actually have the same prices, similar equipment, similar seats, similar service, etc. The main factor in what pax choose is often FF points.
I have flown domestic in the last three years on Delta, American, United, US Airways, Southwest, Frontier, AirTran, JetBlue, Virgin America, Alaska Airlines, Allegiant Air.. all in economy/coach, and frankly I can't figure out for the life of me what in the United States is "low cost carrier" and what is "full service". In coach, they are all the same. Allegiant is the only one that had some difference- they don't give even a glass of water free but then I had paid 1/3rd of what other airlines were charging on that route, so can't complain. The differences are, some airlines have in-seat TV screens, some don't but that's again very aircraft type specific. Apart from that, its all same- Boeing 737 or A320, 3-3 seating, in-flight service includes one (or at max two) rounds of soft drinks/coffee. The only truly "different" experience was when once United put its international configured Boeing 777 on IAD-SFO flight. That was the BEST domestic flight ever.. complimentary blankets, pillows, headphones, in-seat TV with a huge variety of US and international movies, TV shows and music, and of course the nice roomy feel of being in a 777
The full service is the ability to go from pretty much anywhere to pretty much anywhere else. I can go from my local hillbilly airport all the way to the middle of Africa by buying a single ticket on a full service carrier.
The low cost refers to how the airline is operated, and not how much the passenger pays. They have limited networks. While I can call Delta and go anywhere, with Southwest I can only go to a limited number of places.
However, even some of the "low-cost" carriers have extensive networks now. For example, Southwest's to the point now where you can get from pretty much any mid-sized (or larger) metropolitan area to another. They're not going to fly into some of the smaller airports, but usually those are ones that only have subsidized flights. (The American West is a notable counterexample to that, but I can't help but think they want to rectify that somewhat.) That's why they're so popular.
Of course, if you need to fly to or from a smaller airport, or you need to fly internationally, the "full-service" carriers are your best bet. (Though I would rather see solid train service serving those communities that have subsidized air travel, but that's a rant for another thread.)