[xnx]

Keep going with that thinking. What if trains were autonomous, electric, exactly/efficiently sized to what they were transporting, didn't require expensive/dedicated tracks, and could go directly between any 2 points? You end up with autonomous vehicles.

[bobthepanda]

Trains are nice because they don’t require massive reconfigurations to hold varying crowds of people and the things they carry. People move furniture on subways all the time. There isn’t really a ‘perfectly sized’ personal vehicle; even now, just the simple bifurcation between a normal and XL taxi leads to longer waits for the latter, and god forbid you need special accommodations like for a wheelchair.

Car-like vehicles have massive inefficiencies, because the act of merging into and out of other lanes is inefficient.

A train line can carry up to 80k people per direction per hour. The FHWA’s estimate of a car lane car capacity is 2k people per direction per hour. And because cars have to eventually dump onto a surface network that requires timed cycles so that pedestrians and cyclists can cross the street, these low capacity segments are actually the bottleneck.