Maybe I can give a UK perspective on how this is possible. I'm not sure whether we can say that rail travel is profitable here, it still receives substantial government subsidy each year, but it is successful in that last year saw a record number of rail journeys taken.<p>I'm not sure what the parking situation is like in the US but here if you work in a major city car parking will cost you at least $100-150 per month, London is much more expensive. A lot of our suburban railway stations allow free or discount parking so even if you can't make your entire journey by train you can park and travel into the city by rail.<p>When it comes to longer journeys the tickets are sold on a reverse pricing basis, if you buy in advance the first 10-20% of tickets for a train are sold at the cheapest rate, sometimes a 200 mile journey costs as little as $20. If you buy a ticket on the day and during a peak period you'll pay a lot more. This structure however seems to result in more of the trains being full more of the time as pricing reflects the demand.<p>Also faster trains all fitted with wifi make longer journeys much more simple. I often travel into London and buy an advance ticket that costs around £25 ($35 ish)the train at 125mph takes half the journey time of the car and you avoid parking charges and the london congestion charge. I also get to work the entire journey for a similar cost to the fuel alone. It really is a complete no-brainer, you'd have to be stupid to want to drive.<p>That is I suppose a long reason for a simple answer. When it becomes more attractive to travel by rail people will leave their cars at home.