Artificial intelligence used to measure urban sprawl in Canada

“We are a suburban country,” says Sasha Tsenkova, a professor in the School of Architecture, Urbanism and Landscape Planning at the University of Calgary, with whom we shared our analysis.

In total, 1,700 square kilometers have been added to urban areas in Canada’s nine largest major cities. It’s as if we’ve collectively built an area three and a half times the size of the island of Montreal, since 2001.

And because urbanization has, on average, grown faster than population growth, (+34% vs. +26%), every Canadian on average occupies more and more land, away from city centers. In 2001, the population of the nine major megacities occupied an average of 317 square meters2 of urban land. In 2021, this statistic jumped 19 million2which is an area equivalent to one or two additional parking spaces per inhabitant.

“Urban sprawl contributes significantly to greenhouse gas emissions,” Sasha Tsenkova recalls. It has an economic, environmental and social cost. Instead of building new neighborhoods, we should condense existing neighborhoods and add services and shops within walking distance, according to experts.

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How did we do?

Canada’s most recent maps of natural resources for the country’s urban lands date from 2015. To cover the period 2001-2021, we trained an artificial intelligence algorithm to recognize urban areas. From several thousand satellite images covering nearly 47,000 square kilometers, this computer program drew the maps shown at the beginning of this report, based on the geographic boundaries of major cities in 2016. For more details, see the methodology at the end.

The development of low-density segments designed for automobiles was a very profitable business model in the 1960s and 1970s, and that is what we continue to favor today. According to our analysis, in neighborhoods built less than 20 years ago, 60% of residents live in single-family homes. But this type of neighborhood exacerbates road congestion and pollution: 81% of residents use their cars to go to work. By comparison, in historic neighborhoods, only 38% of residents live in homes and 65% drive to work.

“Bad planning decisions are to blame for our transportation problems,” says Catherine Morency, a professor at Montreal Polytechnic and holder of the Canada Chair for Research in People’s Mobility. The expert explains that the best trips, in urban areas as well as in the suburbs, are those without motors. If residents are unable to make ends meet without a car, this does not work. For people to get around on foot there has to be a mix in their area, with services within walking distance. And for public transport, a certain population density is necessary, otherwise the low number of users makes the operating costs very high.

In April 2020, Statistics Canada released the proximity index for the entire country. The latter makes it possible to measure the access of neighborhood residents to a series of services (grocery store, pharmacy, nursery, school, public transportation, park, etc.) within walking distance. We compared this index, as well as Canadian census data, with our geographic data.

While the COVID-19 pandemic has accelerated the adoption of remote work, it also risks triggering a new wave of urban sprawl. Catherine Morency explains: “Before the pandemic, we were already seeing that people who work from home have a greater tolerance for their travel time. In other words, they agree to live far away, because they travel a lot for their work. And when they do, they have less access to public transportation. Thus, they travel by car to meet their needs.”

And even if these remote workers travel less often than others, we must not forget the costs related to urban sprawl, whether for new roads, drinking water pipes, power lines, or sewage networks. “When you fall below a certain population threshold, spending on this infrastructure exceeds revenue from property value taxes and municipal bills,” says David Washsmuth, a McGill University professor and chair of Canadian research in urban management. In other words, we support these sparsely populated neighborhoods. »

A September 2021 study by the City of Ottawa estimated that low-density developments built on green land cost the municipality $465 per person per year. As for densely populated real estate developments, which are built near already urban areas, the municipality is instead collecting a surplus of $606 per inhabitant, after all expenses have been paid. This analysis, conducted by Hemson Consulting, takes into account capital expenditures and operating costs. In some municipalities, particularly in Western Canada, real estate contractors have to pay for infrastructure installation.

Although it is expanding more and more, some major cities have nonetheless managed to condense their territory. In Edmonton and Calgary, despite exceptional population growth in 20 years (+47% and +52%, respectively), the number of people per urban square kilometer has also increased (+5% and +3.3%). “Regulations for Calgary suburbs improved in the 2000s, as Sasha Tsenkova, Alberta Professor of Architecture and Urban Planning, attests. Double the density thresholds.”

Despite this positive assessment, these two cities remain among the most populous in the country. Calgary’s density is 21% lower than the average of the regions studied in our analysis. The trend is the same in Edmonton, with 39% lower.

Greenbelt around Toronto Source: Green Belt Foundation

Over the past twenty years, the Toronto area has also succeeded in increasing its density. Although 1.3 million residents have been added to its territory, it is still the most densely populated city in the country. “In 2005, Ontario put in a green belt around the city, to contain the sprawl and protect the land,” explains David Gordon. They made a development plan around this area that has teeth. »

In Vancouver, in addition to the mountains to the north, the ocean to the west, and the US border to the south, territorial law also protects farmland. “There is very little land available,” stresses David Gordon, a professor at Queen’s University. Therefore, the city had to grow in height rather than width. The province has also encouraged urban development around its metro stations. Of all the major cities studied, Vancouver experienced the lowest density loss. It is still the second most densely populated area in the country.

Skytrain, Vancouver Underground Photo: Radio Canada/Maggie Macpherson

The results were less rosy for other major cities, such as Montreal, whose density has decreased by 10% over the past 20 years. “We’ve spent a lot of time worrying about the island, when the problem is all over the island,” says David Gordon. “The problem is regional planning and development in Montreal. The Quebec government has also been working for several years to develop a national policy on architecture and land use planning.” It is scheduled to be published in the spring of 2022.

According to David Wassmott, historical context can also explain the difference between Montreal and other major cities. “In Toronto, for example, you have huge, newly built towers surrounded by a sea of ​​single-family homes that were built decades ago because the city grew along with the growth of cars.”

But in Montreal, when cars became democratic, the city had already grown, with denser neighborhoods made up of multifamily buildings, the researcher adds. On the island there are few houses and those who want to live in this type of building buy new ones on the northern and southern shores. With real estate prices still low in Quebec compared to other provinces, new real estate also tends to be more spacious than anywhere else in the country, which only exacerbates the phenomenon of sprawl.

To slow this exodus to low-density suburbs, especially families, David Washsmouth believes that counties need to review their laws and regulations.

“We build two opposites in Canada: family homes or apartment towers. But it’s hard to build something in between.”

David Washsmouth, Canada Research Chair in Urban Governance

The lack of choice pushes people with financial resources and children towards suburbs, even if the latter are willing to stay near urban centers.

There are also strong incentives to become a homeowner in Canada, including financial assistance for the first purchase, but there is almost no advantage in staying a renter. The expert adds: “We find accommodation for rent near city centers and properties for sale in the suburbs. Without a strong control mechanism, the real estate market will result in a lot of urban sprawl.”

“We can’t try to save time by buying electric cars,” said Sasha Tsenkova of the University of Calgary. This problem must be addressed from the source. We need to revitalize our mature downtowns and suburbs to sustain families. We need to match the expertise of city planners, building contractors, mass transit planners, and environmental experts to begin to get it right. »

For Catherine Morency, a professor at the Montreal Polytechnic, environmental taxes are also a means. Currently, in Canada, traveling by car is relatively inexpensive. The cost of road congestion and parking pricing remain limited. As vehicles become more fuel efficient, people buy them larger. This means that they are not trying to save. For alternatives to become competitive, each kilometer driven can have a tariff. “I don’t see how we’ll get out otherwise.”

More road sharing, she adds, with more space for pedestrians, bikes and public transportation is also a key solution. These are modes of travel that allow more people to move around while taking up much less space than cars that often have only one person inside.

“Urban development is a very long-term process, states David Washsmouth. Most of the time, when we build something, it stays in place for decades, sometimes centuries. This is the case for individual buildings, but above all for the skeleton of our cities. And what that means Is that the decisions we make now, our grandchildren will live with the consequences.”

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