In the U.S. alone, there's more than four million miles of roads, very expensive to build, very expensive to maintain infrastructure, with a huge ecological footprint, and yet, very often, congested.
În S.U.A., sunt peste 6.5 milioane de kilometri de drumuri, foarte scumpe de construit, menţinerea infrastructurii e costisitoare urmările ecologice, uriaşe, şi totuşi, adeseori aglomerate.