It's an equilibrium thing. People only have a certain tolerance for bad traffic, so to some extent as congestion increases fewer people drive. And vice versa.

It's an equilibrium thing. People only have a certain tolerance for bad traffic, so to some extent as congestion increases fewer people drive. And vice versa. https://en.wikipedia.org/wiki/Disappearing_traffic https://en.wikipedia.org/wiki/Disappearing_traffic https://en.wikipedia.org/wiki/Smeed's_law https://en.wikipedia.org/wiki/Smeed's_law