ET3 over 100 times more "granular" than airports.
With ET3, small access portals are distributed along the tubes like exits on a freeway. It is said that 90% of Americans reside within 15 minutes of a Walmart store. A typical international airport serves a population of about 5 million people. 100 ET3 access portals can be economically distributed over the same 5 million population for one access portal for 50k people (about like the frequency of Walmart stores).
A typical American is more than an hour from an airport, and the last airport built in the US was DIA at a cost of $4.8B
$4.8B could build as much as 1600 miles of double tube ET3 system with a 400mph design speed-- serving a larger area than the typical airport.
