Which is a fair argument, but using the current math it's about half the cost of rail. So even if you need to increase the gas tax in order to "make it pay for itself," you're absolutely not going to do that so much so that you double the cost.

It's hard to make an argument that rail is cheaper than driving without getting into a lot of mental gymnastics, and I really like taking the train when able.

I don't think "cars cost more than just the price of gas" is mental gymnastics, but an exact $ figure we can all agree on will be tough.

Once they become a thing, the price of an autonomous taxi between the cities should approach the real amortized cost of road travel.