Unless you live in NY, LA, Chicago, DC, Boston, Philly, or maybe Seattle, Baltimore and Wilmington metro you have to take a car to the Amtrak station.
With all due respect, that's not true, even assuming you meant 'a major city.' I live in Burlington, VT and I can (and regularly do) take a bus to the Amtrak station in Essex Junction, VT. In fact, I don't even own a car here - I commute solely by bus and bike (when its warmer) and we have a carshare program here (like Zipcar), so I can take a car out when necessary.
Now, Burlington really has exceptional transit service considering what most places our size have, but a large number of small and medium sized cities have workable transit systems. Off the top of my head, I can think of: Bridgeport, New Haven, Hartford and Stamford, Connecticut, Austin, TX, San Antonio, TX, Springfield, MA, Worcester, MA, Fort Lauderdale, FL, Orlando, FL, New Orleans, LA, and Davis, CA - and those are just ones that I've personally been to (yes, I realize some of these qualify as 'major cities'). There are probably at least fifty or sixty others.
Now I admit that trying to navigate an unfamiliar bus system isn't the easiest thing in the world (but Google Transit is making this much simpler), but that doesn't mean that you have to drive to any Amtrak station that's not in a major city - there are many times viable transit options. Now many places haven't invested in transit and have heavily suburbanized development, but that doesn't mean that you have to drive in many of the small cities where other options exist. And please don't confuse the fact that many people choose to live in areas without (and not suited for) transit service with whether or not transit is available in the city in question, and whether that transit goes to the Amtrak station.
Irregardless of this particular prediction, I think that fuel prices are inevitably going to rise and that we really need to begin investing in a wide variety of transportation modes and in development styles that permit walking, biking and transit use (and almost also universally create highly desired, livable communities).