Jane Jacobs: the street as the engine of the city

Jane Jacobs changed twentieth-century urbanism by looking at the street from the pavement. With no academic training in planning, she wrote The Death and Life of Great American Cities (1961) against the modernist ideas that dominated her time: strict zoning, the separation of functions and the demolition of whole neighbourhoods. Against them she defended an organic and participatory vision of the city, in which the vitality of streets and the social interaction of neighbourhoods are what keep it alive. Her observations of everyday life still shape how urban space is understood and planned.

Her best-known contribution is the defence of urban diversity as the condition of a vibrant city. Jacobs criticised the approach that tore down old neighbourhoods to build large residential or commercial complexes, destroying along the way the social networks that sustained them. Cities that work combine different uses and activities within a short distance — shops, homes, schools, parks — so that people use public space at different hours and the street keeps a constant flow of activity that makes it lively and safe. Jacobs listed four conditions for that diversity: mixed uses, small blocks, buildings of different ages and sufficient density.

Community participation against the plan

Community participation was the other pillar of her thinking. In her confrontation with the large urban renewal projects of the 1960s, and in particular with those pushed by Robert Moses in New York — among them the expressway that would have cut through Lower Manhattan — Jacobs argued that residents must take part in decisions about the future of their neighbourhoods. Planners and architects should not impose their vision from above without attending to the needs and wishes of the people who live there. Her alternative is planning that respects social dynamics and local knowledge: a more democratic and inclusive urbanism.

Jacobs also defended density at a time when most planners promoted suburban dispersal. For her, density was not a problem but an asset which, well managed, enriches urban life: a high concentration of people in a small area favours social interaction, the creation of local businesses and the efficient use of public transport. Against expansion into the suburbs, she proposed strengthening the dense neighbourhoods of central cities as the way to create more sustainable and dynamic communities.

Active streets and safety

The idea of active streets is central to her work. Jacobs believed that streets are the soul of the city and that their continuous activity is essential to safety and social cohesion: the eyes on the street of neighbours, shopkeepers and passers-by keep watch without anyone ordering it. Against the theories that proposed highways and grand boulevards to solve mobility, she insisted that local streets must be designed for pedestrians rather than for cars. A street where people walk, cross paths and go about their daily lives is a safer and more attractive environment for everyone.

Jacobs's contributions — diversity, density, neighbourhood participation, the critique of large-scale urban renewal — remain influential, and her method, observing the daily experience of the city before theorising about it, has inspired generations of planners, architects and activists seeking more humane and liveable cities. Much of what is now called proximity urbanism or the 15-minute city was already in her pages of 1961.