Agreed. But subways cost so much more, $1 billion per mile in many cases. The Boring tunnels look to be around $10 million per mile.
The per mile cost is misleading because it's really the stations that are super expensive, rather than the tunnels.
Why are subway stations so much more expensive? Because of the size, right? The Boring stations seem to be much smaller.
Where by "much smaller", I guess you mean "able to transport many orders of magnitude fewer people".
Absolutely fewer people. Yes, I agree a subway is better than car tunnel, when costs are ignored. But LV doesn't have $30B to build a subway tunnel. But a car tunnel can be built for roughly 100x less, $300 million.
Uselessly, unless you have only a few people to move. Then, taxis work better.
Yup, expropriating land and blocking main roads for months while you dig down and pour concrete for a station is expensive. Although some newer metro lines like Barcelona's line 9 are able to fit most of the stations inside the larger tunnel so that they only need to dig elevators straight down to them which ends up being a lot cheaper.
Why don't they bring the tunnels up to the surface for stations?
Too many things in the way (building foundations, other metro tunnels, sewers, etc.). It's only possible in lower density neighborhoods.
$1B per mile is institutionalized wholly-legal corruption, not tech.
But you can retrofit corruption to any technology. Even to underground traffic jams.