Planning Theory and Current Issues

Past Planning Theory and Current Issues

Past Planning Theory

The 15-Minute City concept can be seen as an accumulation of the human-centred planning theory developed over the last century in response to modernism, car-centric planning, and urban living conditions. Many theorists have proposed a combination of three elements: the neighbourhood as an organizing unit, the importance of diversity, and the links between quality of life, built form, and active transportation, as key to human-centred planning (see Fig. 6).

Neighbourhood The 15-Minute City is based on the idea of complete neighbourhoods where “one has safe and convenient access to the goods and services needed in daily life.” (City of Portland, 2012, p. 76). Complete neighbourhoods typically include affordable housing, fresh food, commercial services, recreation opportunities and open space, culture and entertainment, and opportunities for civic engagement (City of Portland, 2012). This concept is an important component of contemporary municipal planning, but the idea of the neighbourhood as an organizing urban form goes back over 100 years.

Ebenezer Howard (1902) and Clarence Perry (1929) both used fixed organizing units in the development of city plans. Howard’s (1902) Garden City was designed as a 1200m circle around institutional uses and parks, while Perry’s (1929) Neighbourhood Unit was envisioned within an 800m radius of a school. Both envisioned self-contained districts linked to the broader region by trains or cars, with the Neighbourhood Unit being surrounded by commercial uses on arterial roads. Howard (1902) and Perry (1929) developed their respective concepts as a response to issues of urban living conditions of the time, such as poor sanitation and high pollution levels (Howard, 1902), and the increased use and speed of cars (Perry, 1929), with both responding by focusing on neighbourhood scale solutions. More recently,

Planning Influences

Ebenezer Howard Clarence Perry Jane Jacobs

Neighbourhood

Leon Krier Congress for the New Urbanism Jan Gehl Diversity

Quality of Life

Figure 6: The 15-Minute City is based on concepts from a range of past planning theories

Leon Krier (1984) and the Congress for the New Urbanism (CNU) (2001) have adopted the idea for contemporary cities. The CNU (2001) uses 5-minute intervals around commercial centres and Krier (1984) proposes a city made up of 10-minute communities.

The neighbourhood can also be thought of as a social unit. Jane Jacobs (1961) defined the neighbourhood at three different scales: the street, district, and city as a whole. The street is most similar to the previous examples, where a neighbourhood forms around a cluster of local businesses or a ‘main street’. At a district level, the neighbourhood is a social and political unit. Jacobs (1961) stressed that the success or failure of a neighbourhood depends on self-government, and noted that a district should be large enough to have a political voice to mediate between the small, powerless street neighbourhoods and the large, powerful city neighbourhood or government. Because the city holds and distributes resources but is unaware of minute issues at the street level, a district made up of street neighbourhoods can ensure that local issues are recognized and that streets are able to participate in city-level decision making (Jacobs, 1961).

Diversity Another important element of complete neighbourhoods is diversity, which also reflects past theory. While planning in the modernism movement focused on the separation of different uses (le Corbusier, 1933), more contemporary theory states that cities are diverse by nature (Jacobs, 1961) and that areas should combine a mix of uses and provide for all aspects of urban life (Congress for the New Urbanism, 2001; Krier, 1984). This is important for the economic health and social cohesion of a neighbourhood, as diversity will encourage interaction between disparate social groups (Gehl, 2010; Jacobs, 1961). Without sufficient diversity, a neighbourhood may become inconvenient for local residents who might otherwise choose active transportation, which can diminish street level activity and create a perception of danger or neglect (Jacobs, 1961).

Quality of Life Within a neighbourhood, there is a strong link between quality of life, active transportation, and the built form. The physical and aesthetic qualities of a space can encourage or discourage the choosing of active modes of travel. While some trips must be done via walking (i.e., from home to the local bus stop or from a parking space to a shop entrance), the remaining optional trips will only utilize active transportation when the city supports

it as an attractive option (Gehl, 2010). This can take place in terms of the built form, such as short blocks, diversity of uses, and integrated public parks (Jacobs, 1961), or in more aesthetic forms, such as active building frontages, high-quality public spaces, and urban greening (Congress for the New Urbanism, 2001). A neighbourhood that encourages walking or cycling allows people to take advantage of the diversity and completeness and can encourage the creation of

It is impossible to take advantage of multiplicity of choice without being able to get around easily

new or improved public spaces (Gehl, 2010). However, a poorly designed neighbourhood can serve as a barrier. As Jacobs (1961) writes: “It is impossible to take advantage of multiplicity of choice without being able to get around easily” (p. 340). Thus, a built form that supports mobility, particularly through active transportation, is a key component in quality of life.

Summary All of the theorists above were looking for solutions to issues of urban quality of life and car-centric urban design, from Howard (1902) and Perry (1929) at the turn of the 20th century, to Jacobs (1961) and Krier (1984) as a response to modernism, to the CNU (2001) and Gehl (2010) in the 21st century. Over the span of more than a century, these theories all recognize the link between neighbourhood level design, diversity, active transportation, quality of life, and social benefits. The 15-Minute City builds on these links to emphasize the aspect of time and the importance of proximity to specific daily needs.

Other theories have similarly used timebased planning as a solution to past planning. Da Silva’s 20-Minute City takes a transportation-based focus, restricting and reorienting the built environment to increase accessibility (Moreno et al., 2021). The idea focuses less on the social interaction and proximity aspects of the 15-Minute City in favour of increased mobility through transportation. The 15-Minute Life Cycle City in China takes a health and sustainability-based approach to proximity, ensuring an efficient use of resources and opportunities for healthy living (Weng et al., 2019). Both theories rely on access to daily needs as a key to reaching their goal.

Current Issues

The 15-Minute City also relates to current issues facing urban regions. Across the world, people and cities are embracing a shift towards more sustainable forms of transportation (O’Sullivan & Bliss, 2020). Cities are responsible for 75% of global carbon emissions, with only half of the world’s urban residents living with convenient access to transit and green space (United Nations, n.d.). Reconfiguring the way cities are designed and managed to enable a shift in everyday travel behaviour is essential for impacting global climate change (United Nations, n.d.).

One solution being implemented is Transit Oriented Development (TOD), which focuses density and services around rapid transit stations. Increasing access through rapid transit is important for linking together large urban regions, but some TOD implementations are resulting in islands of walkability (Sisson, 2020). In these cases, the walkable urban form surrounding the transit stop does not extend out into the surrounding community, limiting the access to these areas by local residents. Too much of a focus on TOD also excludes those who are not in proximity to the rapid transit network (Wilson, 2020). Instead, there are calls to move away from the historic approach of long-distance mobility through increased speed to one of local accessibility through decreased distance (Herriges, 2019). When the distances being travelled are reduced, particularly within the limits of a 15-minute walk or cycle journey, speed becomes less important.

There is also increasing focus on the past injustice caused by historic planning and broader economic forces, particularly as it relates to central and suburban areas. The modernism era of planning marked a shift in the design of cities. Le Corbusier (1933) and others who influenced early 20th century planning sought to reform cities in response

to what were then seen as poor living conditions and social disorder. The resulting rationalization divided the city into mono-functional zones with large open spaces separating buildings and uses. This created a form that was best navigated through the car, for which networks of highways were constructed to connect the disparate districts. In many cities, highway construction and other urban renewal projects, such as demolishing and rebuilding neighbourhoods, disproportionately targeted marginal and racial communities (Archer, 2020). The connections between new affluent neighbourhoods and employment in the city centre were enhanced at the expense of cities’ least advantaged residents.

In more recent decades, the forces of globalization and gentrification have further contributed to the spatial and economic polarization within cities. The shift in the Global North towards a knowledge-based economy has extended the wage gap between high- and low-income earners and created high demand for central urban locations within large, global cities (Musterd, 2006). The resulting increased competition forces lower-income groups out of a city’s most attractive areas (typically those that are central and well-serviced), and displaces them to outlying areas (that typically have fewer services) (Hedin et al., 2012). These and other forces of gentrification have led to cities that are segregated on the basis of access to resources (Madanipour, 2004). The richest citizens are able to choose the most desirable locations, while the poorest citizens are forced to live in the marginal and outlying spaces that are available to them.

With regard to the 15-Minute City, many city centres and desirable neighbourhoods already have many of the qualities for which the concept is advocating (C40 Cities Climate Leadership Group, 2020; Rudlin, 2020). City centres are typically denser, have a more connected street grid, and offer more services and amenities for residents than the surrounding areas. These surrounding suburban neighbourhoods (typically built after 1950, with low-rise, single-use zoning and car-centric infrastructure [see Fig. 7]) are lacking the proximity, density, and diversity needed to be 15-Minute Cities. The winding, hierarchical road patterns translate into longer trips and less direct connections for walking and cycling, and create a hostile environment for active transportation (Ledsham & Verlinden, 2019). A built form dominated by single-detached housing lacks sufficient population density to support services and amenities within walking or cycling proximity, and historic single-use zoning policies often prevent the addition of diversity in terms of use and housing form (Novakovic, 2019).

The forces of gentrification have led to cities that are segregated based on access to resources

Many urban professionals have identified these problems with suburban areas and proposed solutions. There is also a recognized desire from citizens to live in more compact, walkable neighbourhoods (Brookfield, 2017; Toronto Public Health, 2012). Some of the proposed strategies involve adding density and diversity through redevelopment of underused locations (Dunham-Jones & Williamson, 2009; Tachieva, 2010), but this approach does not necessarily positively impact the areas with the most need. Beyond the previously mentioned issues linking increased desirability with gentrification, a development-based approach typically relies on private investment, which may target locations and projects that maximize profit instead of increasing quality of life for the city’s least advantaged. There may also be resistance from those who perceive suburbs as car-loving places and either are unaware of the broader social issues or have an interest in maintaining the status quo (de Francia, 2019; O’Sullivan, 2021). What is needed to solve these interconnected issues is a method of reducing the disparity between different groups within cities and providing for the daily needs of residents regardless of location and socioeconomic status. The 15-Minute City is seeking to provide this, however there is some doubt as to whether the concept will repair these urban fragments or increase disparity between the affluent city centre and the disadvantaged suburbs (O’Sullivan, 2021). In order to ensure that the 15-Minute City is for all city residents, it is essential to ground the concept in the idea of justice.

CITY OF CAMBRIDGE GROWTH & INTENSIFICATION STUDY

Figure 7: Suburban land use patterns and car-centric infrastructure create environments that are hostile to active transportation (City of Cambridge, 2016 [top] & Khan, 2018 [bottom])