Expanding urban boundaries have been with us since cities started to grow. Toronto and Montreal are no exception to this rule. Canada's two largest cities had fewer than 500,000 inhabitants a century ago; they now have more than five and three million people respectively. It's only natural that their urbanized areas have grown and that the last century's increased prosperity should have been accompanied by constant expansion in the number of single-family dwellings surrounded by a little greenery: That's what most people want.
Yet our new century's urban ills are being laid at the door of urban sprawl and laissez-faire urban design – including the destruction of farmland, the decline of our downtown cores, global warming – even the obesity of North Americans, who now prefer to drive rather than walk! In reality, however, the suburbs aren't as guilty as their accusers claim.
I argue that urban growth threatens neither our supplies of agricultural products nor the quality of our environment – because farmers now produce more on a small plot of land than they did only a few decades ago. Grain production has increased by 150 per cent on average since the 1950s and, accounting for inflation, the average price of food today is one-third of what it was then. These productivity gains should mean that urban sprawl has had little direct impact on the amount of woodland in North America, because many farming operations that weren't profitable in the past have once again reverted to forest.
Nor is it fair to argue that the expansion of the suburbs is a zero-sum game that has occurred at the expense of our cities' downtown cores. If that were the case, why do developers rush to promote construction of residences and retail stores on the vacant lots in Canada's downtown areas as soon as zoning bylaws are amended?
(The situation of U.S. cities is more complex, primarily because of factors in their urban cores that hinder development. These include high crime rates, the poor quality of public schools, and environmental regulations that can discourage the use of former industrial areas.)
The main complaint of those who oppose urban sprawl, however, is the fact that most consumers clearly prefer cars over public transit to satisfy their transportation needs. Here, too, the facts tend to undermine conventional wisdom.
First, an increase in the number of cars does not automatically lead to a decline in urban air quality. That's because the technology of the vehicles in question is much more important than their numbers. Despite a large increase in the number of cars since the end of the Second World War, the air quality in major North American cities has improved substantially over the same period.
Second, the level of pollution emitted by a car depends more on the nature of the travel than on the distance. A busy highway where the cars move at a constant high rate of speed causes much less pollution than a city street where vehicles stop and start constantly. Paradoxically, the construction of new highways to make traffic flow more smoothly can actually help reduce pollution from cars.
Third, many businesses have relocated closer to the suburban homes of their employees. As a result, the average time taken by North Americans to commute from home to workplace has not increased in recent decades.
Many pundits advocate draconian measures to stop urban sprawl. In reality, the onus is on the pundits to prove that the choice of most consumers as to where they wish to live – and the shape and form of the communities that result – is really a tragedy rather than a problem that does not exist.
Pierre Desrochers est directeur de la recherche à l'IEDM.