Urban sprawl grew out of affluence, when, for the first time, significant numbers of households could aspire to home ownership, a car in the garage and a good-sized yard. In the 21st century, it's clear that large, far-flung cities are at best a mixed blessing.
Long commutes lead to high carbon emissions and sedentary lifestyles, and suburb zoning, according to some city planners, leads to lower social capital, as people feel less connected to their neighbours. "Smart cities" are planned to reverse this trend by creating urban villages that are compact and self-sufficient, rather than suburbs. When residential areas are close to commercial districts, green space and recreation destinations, walking and cycling for routine travel become viable options.
"Smart growth means building livable communities without hurting the environment; communities that are healthy socially and economically and environmentally," says Ray Tomalty, adjunct professor in the School of Urban Planning at McGill University.