we also have to remember the massive highway-ization was a post war eisenhower era cold war strategy to make america more mobile.
except it didn't end there. for example, when i was in college, reagan rebuilt and raised all the perfectly fine overpasses along I-75 in nw ohio so that tanks could be transported on flatbed trucks. afaik rail wasn't seriously considered. and when that work was done? they closed the tank plant.
so yeah all that said, all in all the amount of money thrown at roads is ridiculously way, way out of proportion to public transit $, never mind TOD, in the usa.