For completeness, this is a post of mine to Seattle Transit Blog from a few weeks back:
Your local ex-motorist (Ben W.) finally had his first rail trip last weekend, down to Portland and back, and I've some thoughts on the process, which I'll be sharing over my next few posts.
The first question, for the many who have never taken regional rail or thought much about it, is why take rail? What does Amtrak have to offer, compared to the other options: the road-trip or the short distance flight?
I'll skip over flights here because they're easy to dismiss, particularly if you're paying for them. They're almost 3x the cost ($159 vs. $56), and while they're faster in flight, when you count travel to and from the airport and security clearance time, the advantage wears down.
Cars on the other hand, you may see as your old, trusted companion for these trips, when perhaps they shouldn't be. It may seem obvious to you that the $60 round trip cost of a train ticket is more expensive than driving yourself, but it's as often false as true. One of our natural human biases is that we often ignore costs which accrue over time, if we're not confronted with them directly. For example, as I mentioned in an earlier post, depreciation costs thousands a year, but you think more about this cost if you're confronted with it each year than if you buy the car outright. This is despite the fact that the salable price for your car continually declines, so the economic cost is the same. Likewise, a roadtrip may feel like a liberating, low-cost experience, while the cost of the Amtrak ticket may seem high, when in fact the out-of-pocket costs are the same (for a single traveller, with the fuel efficiency below). You might think differently because paying the cost of fuel isn't a precondition to starting your voyage, the costs come up after you've committed to the trip, and are thus easier to dismiss.
I put together this calculator to quantify this point. Note that you can edit the calculator values to put in your own car's fuel efficiency, for example.
Now, this shows Amtrak and driving costs (for the single traveler) are essentially equal, on average, but there are qualifiers on both sides of this comparison. First of all, fuel costs are by no means the full cost of the car trip. Other costs include depreciation from the mileage you're putting on your car, the potential cost of an accident, and the cost of your time in the car. Just like busing it to work, in the train you can work, read, or watch a film, while you can't do the same in a car, and this has real value, as we'll see.
Finally, the train is much more fuel-efficient than your car. While it's difficult to say exactly how much more, wikipedia puts the figure somewhere between 1.25x and a whopping 20x the efficiency in the train. Note too, that the unimpressive lower figure is dubious, and more likely to be in-line with other rails systems, at 6x or better. Naturally, a train which uses less fuel also emits less pollution, to a similar extent. Adding to this effect is that rail, as point to point transport, encourages walkable, dense cities, rather than the highway system's sprawl, so your use has long-term effects even beyond the benefits of the ride.
On the other hand, to be fair, cars do offer you greater flexibility, in timing, destination and route, and, importantly, the fuel and depreciation costs are fixed, while the rail costs are per-person. So you can pile 5 people into a car and travel at a fraction of the cost of the multiple rail tickets you'd need to buy. So there are legitimate reasons that it may be reasonable or necessary to take a car.
But even these points may not be as clear as they seem. While 5 people splitting the costs may be a clear win, 2 people is much more common scenario, and isn't necessarily clear-cut. Even though the rail costs are now twice as much, this extra $60 over the cost of fuel has to then be weighed against the value of your free time. That $60 works out to just $5/hr of time ($60/(2 people * 6hrs round trip)), and as I mentioned, rail time is computer/book/movie time, while car time is often just that. Now, I'm not saying one is always and everywhere a clear win over the other, but along with the environmental and city benefits, one might think that paying $5/hr to be free to work or to write may be well worth it. Put another way, even at minimum wage, it takes fewer hours of work to earn those costs than the time over which you enjoy the benefits. At a standard wage (WA median household income / (52 wks * 40hrs) = roughly $30/hr), you're each working for an hour to liberate yourself for 6.
So there you have it, for 1 person it's a clear win, and for 2 or more, or for last-minute, higher-cost purchases, you should weigh the time and environment you save against the costs you pay. The point here is not to say that we should never need or use a car, but to give these things their appropriate measure, and have them coexist. So for your next trip to Portland or Vancouver, consider leaving the car at home and checking out Amtrak.
Update: I've got a follow-up post on Families and Discounts, in response to some questions in the comments.