Enormous compared to what? We spend 3.2 trillion a year on Medicare, which is 9.9K a person [1]. Imagine if just 1K per person per year (300B) was spent on infrastructure every year to make mass evacuations over a few days possible. Imagine how great normal day to day travel would be once that is in place, city by city.
No, we don't. As your own source says, it is only $646 billion on Medicare, and $3.2 trillion a year in total combined public and private healthcare expenditures.
> Imagine if just 1K per person per year (300B) was spent on infrastructure every year to make mass evacuations over a few days possible.
Then it still probably wouldn't be enough, and we'd get a lot more value for nearly doubling infrastructure spending [0] if we spent it on something else.
Because the cost to not be in it is enormous.