>Firstly, there should be no real reason for the tunnels to be deeper than about 30-50 feet because sewers and utilities are all concentrated at backhoe depth, which is shallower even than that and building foundations are pretty easy to avoid.
Well, this assumes a flat geography. At highway speeds, nobody likes steep grades in either direction, so at the top of a hill, you'd need a deeper elevator to get to the tunnel network. Today's metro systems also prefer to move people down to the trains with escalators or elevators at hilly areas.
>Combined, those factors imply your numbers are close to an order of magnitude off, and imply a reasonable number of elevators in the 30ish range. There are real challenges they need to solve, but I don't think elevator times or count are one of them.
Even if the elevators teleported you to the tunnel, there is still a loading and unloading time involved. This is true of human transporting elevators as well.
It takes 9.5 seconds for an average car, say a Toyota Corolla, (https://www.caranddriver.com/toyota/corolla) to accelerate onto the highway today. The elevator needs to beat that time (loading, accelerating to move down, decelerating, unloading, and accelerating into the tunnel network itself) or throughput is no better than on a standard highway. And on an on-ramp today, cars don't have to wait for the other car to fully enter the freeway.
>Firstly, there should be no real reason for the tunnels to be deeper than about 30-50 feet because sewers and utilities are all concentrated at backhoe depth, which is shallower even than that and building foundations are pretty easy to avoid.
Well, this assumes a flat geography. At highway speeds, nobody likes steep grades in either direction, so at the top of a hill, you'd need a deeper elevator to get to the tunnel network. Today's metro systems also prefer to move people down to the trains with escalators or elevators at hilly areas.
>Combined, those factors imply your numbers are close to an order of magnitude off, and imply a reasonable number of elevators in the 30ish range. There are real challenges they need to solve, but I don't think elevator times or count are one of them.
Even if the elevators teleported you to the tunnel, there is still a loading and unloading time involved. This is true of human transporting elevators as well.
It takes 9.5 seconds for an average car, say a Toyota Corolla, (https://www.caranddriver.com/toyota/corolla) to accelerate onto the highway today. The elevator needs to beat that time (loading, accelerating to move down, decelerating, unloading, and accelerating into the tunnel network itself) or throughput is no better than on a standard highway. And on an on-ramp today, cars don't have to wait for the other car to fully enter the freeway.