And therein lies the problem for high speed rail in the US. We don't have that supporting network, and we're not going to. We're too spread out in our cities for it to work.
So it's drive 30 miles to the train station and then pay $15 a day for parking while on your trip, like the airport.
edit: all that said, I'm not aware of anywhere that has high-speed rails going outside city centers. But I'm hardly an expert on this - I'd love a counter-example. Japan, for instance, has their bullet trains essentially only between city centers, and subway and light rail supporting it. And that's one of the better rail systems in the world.
The sunk cost argument can be overcome if you make public transport faster than cars, less congestion and parking difficulties is a big change. But you do have to rebuild it first (yes the US had public transport in the past, you ripped it out).
And yeah, if public transit gets better than personal, things will change very quickly. But that path involves trillions of dollars, and just try getting a tax increase voted through for one. I'd love it, but it's not happening any time soon, and certainly not on a large scale.
For example, the last train trip I took stopped a handful of times while we waited for livestock to finish crossing the tracks. High speed trains do not do this.