The freeway system explains so much gigantism in the American car ethic. I remember driving around Switzerland and noting that the widest lanes there are about as wide as the lanes on bridge decks in the US. The widest lanes in the US, on the other hand, are about as wide as the narrowest parking lots over there.
Fun fact: Soviet armor was explicitly designed to weigh less than American armor so that Soviet/Iron Curtain bridges could be built that would support Soviet tank columns but collapse under the weight of American tank columns. Tankers in the Red Army couldn't be over 5'8."