Every second you travel on a highway, at 70MPH, you travel 31.29 meters. The minimum standard (US) highway width for a two-lane highway is 15.8 meters. That means, that one second of travel used at minimum 494.38 square meters of ground space. The average apartment size in the US is 916 square feet or 85 square meters. For every second you drive on a (2-lane) highway in the US, you're driving through a space that could have been instead used for a 6-floor apartment building that could hold 34 apartments.