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 …