I did Stowe via Amtrak. Actually, as we've been talking about it on this site, I did some calculations - using gas at 3.50 a gallon, which by next season should be over 4 dollars:
Car DC to Waterbury VT:
Trip cost = 290
Plane DCA to BTV (Burlington) (I used Travelocity)
Trip cost: $366 round trip on Delta or Continental
Additional: Weekly car rental for the 34-mile, 44 minute trip: $351
Union Station to Waterbury
Trip Cost: $146 round trip coach, 230 on business class (meals included)
Taxi to Stowe: $25
This is a perfect example of why driving is going to be so difficult to get away from...
Using Google Maps, I see that from my door to Stowe, VT (I presume it's the town, not the resort), it's 589 miles (slightly longer if I go up 95 instead of taking 81). By taking 81 (as I generally do when I travel into New England), I avoid almost all of the tolls, or at least the ones in Maryland, Delaware, and New Jersey. That saves me at around $20, if I remember correctly.
My car (a 2000 VW Jetta) averages around 28 MPG, so that trip would only take 21 gallons of gas, or just about 1.5 tanks. We can figure (using your number of $3.50) around $75 for gas each way, or about $150 all told. At that point, it's just about break even with the coach seat on the train, and less when I figure that I don't need a taxi either direction ($25 each way, I save $50).
Of course, that's me being selfish. I'd probably want to invite a friend to share the Stowe-y goodness, right? Even with just one friend, I can cut my cost in half. If I have another friend who packs light, and doesn't get carsick from sitting in the back seat, I can I reduce my cost to a third of the train, and plus we get all the joy of a road trip...
So, for $50 bucks in gas (each), two friends and I can make it to New England for a weekend of skiing.
That's definitely better than $150 each, or $230 for business class seating.
But, you've said before that you're looking forward to having the high price of gas force people into changing their mindset. If you're dropping $230 on business class seats instead of $150 coach seats, then you probably wouldn't feel the pinch of $4 gas too much, either. And if you're driving something that gets 15 MPG (average), then something tells me you're not bopping around town in a Mini Cooper... With a hybrid or even a conventional car with good gas mileage, it will take a LONG time before driving with more than one person costs more per person than flying/train/etc. If the cost is the motivating factor we're looking for, then we're probably better off trying something else, like dramatically dropping the cost of train or bus travel.
I think a lot of the people that I think you're suggesting should change their mindset about driving everywhere (and turning to alternative forms of transportation), may not be able to. They're probably more likely to give up on traveling (and the activities that they'd do while they traveled), which is NOT good for tourist-based industries.
If cost were my only concern, theoretically, it would have to be more than twice as expensive to drive as to fly or take the train somewhere (presuming I've got one passenger) for it to be worth my while to not drive on a trip.
In other words, for me to choose to take Amtrak over driving to Stowe (for cost considerations only), it would take gas prices of nearly $15/gallon to make it worth it for my friend and I.
Figure in a second passenger in my car, and we're looking at $23/gallon for the break-even.
$4 gas is scary, but it's a loooong way from $23 gas!
PS - Just for grins, I checked Greyhound prices. A round-trip ticket to Burlington (from DC, the closest station I could find to Leesburg), 7-day advance purchase, is $130. To get a refundable ticket, it's $204. At that price, it's nearly the same as the train, which doesn't make any sense (from a marketing standpoint) at all... Who'd take a bus over a train, if they had the choice?
PPS - Lou, I reread this, and it started to feel like it might like I was attacking your statements on this... I'm not... I just wanted to follow the line of reasoning that higher gas prices will make people approach things differently... Some people, who can afford to, will do so (but might be compelled to do so anyway, if they have the means). For those who cannot afford to do so, it may mean making bigger decisions (not travelling at all). More unfortunately, there's a long way to go before we hit the break-even point, and who knows how many people will bail before we get there?