Embedding of transit and land planning: Looking for the relevant strategy

International audienceThis presentation will address the topic of the embedding of transit policies and urban planning. We assume here that the combined development of transit and city can guide urban planning toward sustainable development. Moreover, transit appears to be a tool to build sustainable yet mobile cities. We therefore can ask what strategies are put forward in the current urban planning debate and which one can be relevant for a specific situation like, for example, Irkutsk. First of all, the embedding of transit and land planning has historical backgrounds like streetcar suburbs in the late 19 th and the beginning of 20 th century, particularly in northern America. Horsecars, then electrical streetcars, have actually shaped the development of urbanization in the outskirts of the cities, often resulting in a gridiron pattern. Another interesting and crucial milestone was the Copenhagen Finger plan in 1947. Thanks to a light rail system called S-Tog and an ambitious planning strategy, a linear urbanization pattern was put forward. More lately, the Scandinavian ABC cities (Swedish acronym for Labour-Housing-Center), which are suburban towns designed to offer their residents everything they need and therefore be independent, were implemented with the help of the Stockholm Metro. Inspired by these European experiments, American urban planners have built a convenient theoretical arsenal calling up New Urbanism and Transit-Oriented Development concepts, which are now globally known. Whereas New Urbanism is often seen as a reshaping of city design in order to improve quality of life, TOD, sometimes considered as an offspring of theaforementioned doctrine, explicitly addresses the embedding of transit and urbanization. Conceptualized by Calthorpe in 1993, this approach suggests the implementation of community-owned neighborhoods where inhabitants can easily access on foot to stores and services as well as a mass-transit station. The goals are to fight against urban sprawl and congestion, to favor modal shift and to boost local shopping. More generally, TOD aims at reducing car-dependency and its unsustainable effects (air pollution, fossil fuel dependence, social exclusion, etc.). The interplay between transit and land-use policies may permit to avoid unnecessary travel. Several principles are therefore put forward to succeed in such an endeavor:-infill;-town center revitalization (with some negative effects as the increases in rents);-streetconnectivity;-the 3D's (Cervero&Kockelman 1998): Density (particularly within a quarter-mile surrounding the transit station because it corresponds to the pedestrian catchment area), Diversity and Design that " softens " the perception of density;-mixed land-use that allegedly shortens trips and spreads them throughout the week in addition of favoring shared parking;-walkability with minimal parking, non-motorized access, traffic-calming, pedestrian-friendly design of streetscapes and multi-functional environment;-accessibility. Accessibility concerns can point out the complexity of the coordination between transit policies and urban planning. The example of Saarbrucken's station of Burbach, targeted as a TOD center although reachabl