Certainly in the short term, perhaps in the long term, but even automated cars come with externalities we might want to reduce such as costs/inputs of manufacturing, pollution, addition time compares to a fast point-to-point link, etc.

For some popular long distance routes, I could see the Hyperloop being useful. Between all reasonably large cities? Probably not.

You're comparing capex vs opex, once you get past a certain period of time. It's possibly cheaper to build automated cars - we have the infrastructure to do so already, and we're close to having the software - but is it actually cheaper to run them, after all externalities are considered?

> Not to mention it might be economically cheaper to pursue automated automobiles since we already have the roads built.

Automated automobiles won't help cutting trip times, which is the main reason why people pay to fly or to ride a high-speed train.