[pas]

And rewatching the video, I wonder... currently a subway / metro car holds 50-100 people (and there are about 5-7 carriages linked), but subways follow each other at best 3-5 minutes. (Or ~1-2 in Japan in rush hour.)

So about 250 - 700 people are moved in 3 minutes, that's 80-230 per minute. If sleds follow each other by let's say 2-3 seconds, and each car holds 1-8 people, then that's 20-240 people per minute. With the added benefit better granularity, and you don't have to switch lines, metros, you don't even have to leave your seat.