One of the most unfortunate side effects of the urban activism of the ’60s and ’70s is the belief that development is wrong and that fighting it makes you an environmentalist. We know that dense cities are both environmentally better and dramatically more equitable places. Walkable neighborhoods are better than the suburbs for people with a wide range of incomes, and what happens in cities that don't grow is that they gentrify and poor people are pushed out. Trying to fight change makes you less sustainable and more unfair. . . .
the best thing a city can do is densify as quickly as it can. That needs to be said every time this issue comes up, because it’s the only universal strategy that works. That’s the best-documented finding in urban planning—that as density goes up, trip length goes down and transportation energy use goes down.