10 hours of active driving is something completely different than 20 hours being a passenger/sightseer (of which I would spend significant part asleep or reading) In fact I don't think it's safe to drive for 10 hours, you probably need to add several hours of rest, and will still be half zombie after that.

At some point the train becomes attractive. It's certainly a much less stressful option.

That said I must agree American trains are in poor shape compared to other places.

Well-marked, well-maintained, well-signed, and gradient/curve controlled interstate highways are among the easiest for self-driving vehicles. It's just about possible today (but expensive and in some ways legally unsolved).

It would be shocking if America didn't have popular, reasonably-priced self-driving highway vehicles in 14 years to do that (14 years used to match the timeline of Amtrak's 2035 map).

And an additional amount of maintenance costs, vehicle depreciation, insurance, etc. Driving might still come out less expensive, but ignoring all the extra costs makes it look cheaper than it really is.