> I posit that for a city of 500,000 - 1,000,000 it might become practical to have subways and that radically changes the transit equation.
Cities of 500000 inhabitants which have a subway exist. See
Cities of 500000 inhabitants which have a subway exist. See
My family is from Lausanne and I spent a few months studying in Rennes–the size and density plus the metro system makes these cities really pleasingly 'human scaled' in my view. Walking-first center city areas with lots of restaurants/shops, easily accessed from less dense areas by metro+good bus systems+intercity train, but small enough overall to not feel sprawling.