Actually at this time, when Haussmann started its transformation of Paris, people though that the circulation of air was very important for health, and that was

Actually at this time, when Haussmann started its transformation of Paris, people though that the circulation of air was very important for health, and that was one of the reasons of widening the streets and limiting the height of buildings, but the main reason was for allowing traffic of goods and people, and to improve security and control of the population (revolts in Paris had made 3 different political regimes collapse in less than 70 years before that). Today people still value seeing the sky and freedom of movement. I have not been everywhere in North America but usually I saw that big buildings mean wide streets around them.