The sustainable city facing the practice test: introduction

Drawing up an action plan incorporating the principles of sustainable development was the call to local and regional authorities in the document entitled Agenda 21, adopted by the Heads of State gathered at the Earth Summit held in Rio de Janeiro in 1992. The Brundtland Report published in 1987, Our Common Future, introduced this notion of sustainable development by defining it as a development that "meets the needs of the present without compromising the ability of future generations to meet their own needs.″ The Rio Summit document highlighted the three main components of sustainable development: social, economic and environmental. A fourth cultural component will be added later. In the wake of this Summit, sustainable development represents, over time, a frame of reference for public policies in general and urban public action in particular (Gariepy and Gauthier, 2009). In this particular context, making the sustainable city (Emelianoff, 2007) has gradually become an objective that has been integrated into the policies, plans and projects of urban municipalities. The Summit on Sustainable Development, held in New York in September 2015, one of whose goals refers to "Sustainable Cities and Communities" and the Federation of Canadian Municipalities Conference on Sustainable Communities in Ottawa, in February 2016, remind municipalities of this new imperative (Gauthier, 2009). However, sustainable development is still the subject of debate (Mancebo, 2008, Levy, 2010), particularly on the relationship between economic development, which remains associated with growth, respect for the environment and social equity; on the adequacy between the principles of sustainable development invoked by public action and the concrete effects of the measures implemented; on reducing sustainable development to the environmental issue given, among other things, global warming; on the various scales of sustainable development, from global to local. Sustainable urban development (Da Cunha et al., 2005), to which the sustainable city is associated, also raises specific issues such as planning, transportation, housing and governance.

In connection with these debates and issues, this thematic issue focuses on the implementation of the sustainable city. What are the plans, programs and projects that aim to make the city sustainable? How is sustainable urban development conceived? How are these various strategies implemented? To what extent do they contribute to achieving the sustainable city? Five articles are gathered here around these questions. The first two articles deal with Transit Oriented Development (TOD) projects planned as part of spatial and metropolitan development planning, the aim of which is to create high-density residential development poles around a railway station or metro station to tackle the problem of urban sprawl and reduce automobile use. The third article questions the fact that urban sprawl is seen as incompatible with sustainable urban development and is interested, from a flow analysis, in the structuring of regional secondary poles that offer services and local activities. The fourth article analyzes a municipal public action that aims to achieve sustainable districts but, after focusing primarily on the environment, tries to cover other dimensions. Finally, the fifth article also addresses the sustainable city through the district, by examining, from planning documents, the evolution of the residential social dimension in the development of a historic district in relation to its built heritage and its touristic economic function.

Olivier Roy-Baillargeon's article looks back on a crucial period for metropolitan spatial planning, that of the production and adoption of the first Metropolitan Planning and Development Plan (MPDP), of the Montreal Metropolitan Community (MMC), more than 15 years ago. At the heart of this Plan (2011), 155 potential TOD areas (or Transit-Oriented Development) are identified to promote mixed and dense neighborhood development, anchored to public transport nodes. It aims at guiding the future growth of the population and to combat the dispersion of urbanization. This model of sustainable urban planning proposes to make a major shift in planning policies, particularly for suburban municipalities. The proposed analysis opens the "black box" of the negotiations that took place between the different levels of government involved in the production and definition of the MPDP content. Thus, the article underlines that the adoption of this new paradigm of sustainable development by the MMC is not free from internal contradictions. Moreover, it emphasizes that the production of a TOD-based MDPD has been the occasion not only of lively negotiations by local elected representatives of suburban municipalities, but also of several local adaptations of the reference model. Finally, this article presents an indirect interest that of allowing a retrospective glance to grasp the path traveled, by the local elected officials in particular, as regards the recent (re)appropriation of the concept and its principles. This (re)appropriation can be particularly grasped through the representations and actions of the elected representatives in the planning and implementation of the TODs on their territory, as the following article points out.

The article by Maude Cournoyer-Gendron proposes a (re)contextualization of the Montreal model of the TOD, in a diachronic and political perspective. Faced with a relatively malleable and transnational urban planning model, the author wonders about its political trajectory, in the Montreal context, since the adoption of the MDPD in 2011. A quick genealogy of the concept coined by P. Calthorpe and its international diffusion highlights local adaptation processes of the original principles of the TOD or the difficulties faced by municipalities to implement them and achieve the expected results, especially in terms of sustainability. The local contexts in which these projects take place play a major role in the operationalization of the TODs. As such, the author recalls that after the adoption of the MDPD, an original process of support for municipalities, to ensure their implementation, was coordinated by the MMC, that of "innovative projects." But the heart of the article concerns the analysis of the discourse of elected officials (10 elected officials interviewed) about these projects. If the concept of TOD is not defined in detail in the MDPD, elected representatives take it as an opportunity for territorial development. They propose diversified development concepts, which sometimes join the original model. However, local issues strongly color the proposed content and objectives. And implementation sometimes strains the stated principles and objectives. The local constraints or difficulties encountered are numerous. But these projects are also at the heart of multi-level governance at work in the Greater Montreal area. Indeed, they offer an opportunity for elected municipal officials to strengthen their position in relations and negotiations with other levels of public decision-making (regional or national) as well as vis-à-vis private developers.

In the following article, Sonia Chardonnel, Magali Talandier, Kamila Tabaka and Isabelle André-Poyaud argue that sustainable urban development does not rhyme exclusively with urban density and that a form of urban sprawl can be compatible with the sustainable development of metropolitan spaces. By taking the urban area of ​​Grenoble as a field of study, they are interested in urban centralities, not in terms of density and concentration of people, jobs or higher services, but in terms of the flows of daily mobility that are not limited to home-work trajectories. Their analysis of these flows reveals, on the one hand, that most of the mobility is carried out in the proximity within each sector of the Grenoble region and, on the other hand, that these mobilities structure various types of poles according to the motive for traveling: work, purchase, leisure. For the work motive, it is the city-center which, without surprise, prevails; for the leisure motive, three regional centers stand out; and for the purchase motive, displacements generate multiple poles. Thus, secondary poles are created, corresponding to peripheral municipalities in low density areas, which are complementary to other poles. This structuring of the peripheral areas in intermediate centralities thus makes it possible to avoid a territorial fragmentation between distant dormitory spaces and a central city which gathers all the functions. The development of these intermediate centralities would thus be favored in order to offer resources and activities closer to the inhabitants, to favor the modal shift in view of shorter trips and to reduce congestion in the denser central areas. For the authors, the articulation between these various centralities contributes to sustainable regional development.

The article by Richard Morin, Anne Latendresse and Nicolas Lozier takes us from the regional to the local level as it deals with municipal programs aimed at creating sustainable neighborhoods. The authors first present sustainable development as a fuzzy notion that constitutes a dominant frame of reference, especially as regards to public action. This frame of reference rests on three main pillars, social, economic and environmental, which will be complemented by the cultural one. In the case of Montreal, the authors point out that the city's first two strategic plans for sustainable development refer to these three pillars, as does the Districts 21 flagship program, which aims at creating sustainable districts. However, the analysis of the projects supported by this program reveals that the environmental dimension of sustainable development clearly predominates. The global frame of reference has thus been reduced, in practice, to a sectoral one corresponding to the municipal environment department in charge of this program. Following an administrative reorganization, the City's third sustainable development plan puts forward a new program, called Integrated District, under the responsibility of an administrative unit within a central and cross-sectoral department. This experimental program aims at covering other aspects of sustainable development as well as the environmental one, by integrating five municipal programs that concern the district scale. However, although the social, cultural and environmental dimensions of sustainable development are among the five integrated programs, the authors note the absence of an economic program. In addition, although the Integrated District program is related to a cross-sectoral service, the five programs to integrate remain each under the control of a sectoral service, which limits their integration.

Finally, Priscilla Ananian's article also focuses on the district scale in the Montreal context. The author addresses the issue of the sustainable city by dealing with three functions, residential, heritage and tourism of the old central districts, which correspond to the social, cultural, environmental and economic dimensions of sustainable development. The author is particularly interested in the deployment of the residential function in these districts. Firstly, she reviews the evolution of the conception of this function in these districts. To this end, she evokes various phenomena such as "the return to the city" and "the city of proximity", residential construction and densification supported by sustainable urban development frame of reference and the development of urban tourism. The latter relies on the authenticity of inhabited areas while putting them at risk of being distorted. Secondly, the author analyzes twenty planning documents concerning Old Montreal and the districts nearby produced since the 1960s. This analysis reveals a variety of plans and public, private and associative actors that interact; the recognition of the district's heritage, residential and commercial functions that are attractive to the tourism function, but whose overall cohabitation is an important issue; the residential densification, which is reaching its limits in Old Montreal and overflowing into the districts nearby; and the vision of a complete multifunctional neighbourhood that is not fully realized. The author concludes the article by mentioning the instrumentalization of the residential function for showcase purposes of the international city and tourist promotion, as well as the lack of coherence of the interventions and the weakness of the means of action of the public authorities.