Lessons from Lisson Green: an Evaluation of Walkway Demolition on a British Housing Estate

Aprevlously unpublished 1986 evaluation of walkway demolition on a London public housing estate Is re-presented. It compares popularly reported views that the removal of walkways reduced crime with the police crime record for the estate. No general crime reduction took place as was claimed. However, closer examination of time series data revealed some significant changes in crime patterns. Good historical information about events occurring on the estate made it possible to understand the reasons behind these changes. The main effect was in reducing robbery and purse snatches. This was not primarily caused by the demolition of walkways but by earlier design changes. Lessons for future evaluations are Identified. BACKGROUND TO THE EVALUATION A characteristic feature of much British medium-rise high-density public housing built in the 1960s and 1970s was the overhead walkway system (see Figure 1). The concept of "streets in the air" seems to have derived from the ideas of the famous French architect Le Corbusier in his Utopian vision of the Ville Radieuse. Instead of housing blocks being isolated from each other, they were connected by a network of walkways and corridors on several levels or decks above ground. This enabled pedestrians to move around the estate without the need to return to ground level. Address for correspondence: Barry Poyner, 2 Barnsway, Kings Langley, Hertfordshire WD4 9PW. England.