This just seems to be pretty hard evidence that the 20th century interstate/feeder road sprawl model cannot scale. Road networks worked sufficiently when the number of users was small, but the ability of that network to handle traffic decreases exponentially proportional to an increase in usage. For large number of users, it seems like you need a backbone of mass transit, moving most people between known transportation nodes. Car usage, or something like it, should only be necessary at the edges - where not enough people travel there to justify mass transit.