[mitthrowaway2]

High density is what enables mass rail transportation, which is much more efficient than personal vehicles.

[bombcar]

Mass rail is most efficient when it's full.

https://afdc.energy.gov/conserve/public_transportation.html - a full car gets amazingly close to a average train (USA).

And this is seen in that trains are most common where they can be mostly full.

What's scary about that is how quickly busses just get outclassed - they have to be as big as their biggest loads, but they're usually empty.

[mitthrowaway2]

How often do you see a full car? Average vehicle occupancy is 1.67, and has been for years.

[bombcar]

Quite often! But usually in the mirror/kid cam, because I'm driving the family somewhere.