Urban Expansion in Mexico: A Growing Challenge
Over the past three decades, Mexican cities have experienced significant growth, resulting in housing developments increasingly situated further from urban centres. This expansion has led to greater distances between residents and essential locations such as workplaces, schools, hospitals, and various services. In many areas, this growth occurred before adequate public transportation options were available, creating a scenario where travelling longer distances has become an everyday reality, making it increasingly difficult for individuals to forgo the use of automobiles.
A recent study published in Nature Communications sheds light on this significant urban transformation. Researchers from the Tecnológico de Monterrey, in collaboration with the Complexity Science Hub in Vienna, explored the population distribution across 69 metropolitan areas in Mexico from 1990 to 2020. During this period, urban populations nearly doubled, yet growth was increasingly concentrated on the outskirts rather than near the city centres.
In fact, during this time, city centres lost approximately 2.5 million inhabitants, with the proportion of the population residing there dropping from over 40% in 1990 to just 22% in 2020. By developing a model to compare this distribution with a scenario where cities maintained the population density of 1990, the researchers discovered that the average distance from the centre had increased by 28%. This rise in distance correlates with longer commutes, reduced public transport availability, heightened vehicular emissions, and challenges in accessing essential services.
Decentralisation and Infrastructure Challenges
Between 1990 and 2020, central areas witnessed an average loss of about 1,000 inhabitants per square kilometre, while more distant regions continued to gain residents. As people migrated to the peripheries, the demand for essential services and infrastructure in these areas surged. “We need to provide water where it is often lacking, as well as sanitation, waste collection, hospitals, and transportation, because we cannot live in disconnected areas,” explains Alberto Meouchi, head of the Mexico City office at the Centre for the Future of Cities at Tecnológico de Monterrey.
The study highlights that much of the housing development on the outskirts occurred without sufficient transportation, water, drainage, or educational facilities. In Monterrey, for instance, researchers identified an uneven distribution of educational infrastructure: while central areas had available school capacities, the peripheries were lacking in adequate spaces. This trend is illustrated by the significant decrease in residents living within five kilometres of city centres. In Monterrey, this figure dropped from approximately 485,000 in 1990 to 377,000 in 2020, while in Guadalajara, it fell from 866,000 to 626,000.
Moreover, Meouchi warns that this expansion often encroaches upon conservation areas, aquifer recharge zones, and habitats for various flora and fauna. As urban sprawl continues, these vital spaces are increasingly threatened. “We are destroying several ecosystems with this expansion,” he adds.
Factors Driving Housing Development Away from Urban Centres
The rising cost of land plays a crucial role in this trend of decentralisation. The research identifies several changes that facilitated construction on the outskirts, one of which was the 1992 reform of the ejidal system, allowing for some of this land to transition to private ownership and be sold, thereby increasing the availability of land for development outside urban areas.
Additionally, from the early 2000s, access to credit for home purchases expanded significantly, coinciding with private developers constructing large housing estates on the outskirts where land was more affordable. The combination of increased credit and available land spurred a rapid rise in housing production, with the number of homes built yearly soaring from around 50,000 in 2001 to over 1.4 million in 2013. Concurrently, finding affordable housing in central areas became increasingly challenging, as rising prices and a greater supply of cheaper options outside these zones led many to relocate further from urban centres. However, this initial saving may impose costs in other areas, particularly concerning transportation and commuting time.
Meouchi highlights that the most vulnerable populations often bear the brunt of these changes: “Lower-income individuals are those who cannot afford to buy or rent homes closer to transportation and services.”
The Impact of Car Dependency
As cities expanded, there was a notable surge in the number of automobiles. The study notes that the number rose from fewer than 5 million in 1990 to over 40 million. This increase in car ownership has made it easier for people to live further from urban centres and travel longer distances.
During the study’s presentation, project leader Roberto Ponce remarked that urban growth has effectively separated housing from jobs and services, creating areas that are increasingly reliant on automobiles. Meouchi attributes part of the issue to the order in which new developments occur: “We often develop first and then think, ‘Oh, let’s build a road or avenue to connect that area.’”
This method of urban growth also limits one of the most frequently suggested solutions for reducing transportation emissions: transitioning from combustion vehicles to electric ones. While Meouchi acknowledges that electric cars can help reduce emissions, they perpetuate a model where many individuals still require a vehicle for long-distance travel. “There must be a greater reliance on public transportation and less dependence on cars,” he asserts.
A Vision for Multi-Central Cities
In light of these findings, the research team suggests better utilising existing infrastructure and preventing further growth from concentrating further away from urban centres. This approach involves increasing housing availability in consolidated areas, improving transportation connections to new developments, and enhancing other centres within cities themselves.
“We cannot assume that everyone will return to the centres; that is impossible,” Meouchi states. The study advocates for the development of cities with multiple centralities, where housing, jobs, services, and transportation are located in closer proximity to one another. Ponce noted that many Mexican metropolitan areas already have such points, but they are not always well connected or offer equal opportunities.
The goal is to strengthen these central areas and prevent certain zones from accumulating housing while others concentrate jobs, schools, hospitals, and services. The research team also calls for a more effective use of existing infrastructure and directing growth towards locations that can more easily accommodate daily activities.
To achieve this, they recommend better coordination of housing and transportation policies with land use, infrastructure, and economic development decisions. This includes determining where construction can occur, what density is permissible, where to direct infrastructure, and how to connect these areas from the outset, rather than addressing mobility issues after urban sprawl has already occurred.
The study raises several questions for further exploration. Meouchi acknowledges that more in-depth analysis is needed to understand what is happening within individual cities, who is moving, how income levels are changing, and where jobs are being concentrated. The aim is for these insights to serve as a foundation for future research and to better comprehend what changes are necessary in each area. “It is essential that these findings reach decision-makers,” he concludes.
Additionally, the results can be further explored through Centrar el Futuro, an interactive platform that allows users to review how population dynamics and urban expansion have evolved across various cities in the country.