[bombcar]

There's a finite number of trips people can practically do - just because they live next door to work doesn't mean they'll commute more than twice each day (close enough people will return for home for lunch perhaps).

As traffic and travel times lessen, people do travel further and more, but only to a point.

[AnthonyMouse]

But who was contending otherwise? You don't need it to be infinite, to be a problem all it has to do is not allow the reduction in driving because now distances are shorter and sometimes people can walk to not exceed the increase in density because now four times as many people are in the same area. Which it might not have done even without this, depending on how much more often shorter distances cause people to walk.