Intelligibility of Post-War Reconstruction in French Bombed Cities

In the aftermath of the WWII, many French cities faced a great need for reconstruction in response to the heavy destruction caused by the bombardments. Reconstruction plans were developed and implemented at relatively short notice in response to a critical and urgent situation. However, not all cities adopted the same approach: (a) some proposed and implemented a new layout; (b) others tried to recreate the old street layout but with some updates such as widening and alignment; and finally, (c) some have preferred to resort to more targeted interventions. The choice of approach was motivated by various factors associated with the level of destruction, the futuristic vision of the architect or urbanist in charge, or the historic value of the place destroyed. This article assesses the impact of these approaches on the urban tissue by measuring changes in the overall morphology and intelligibility of multiple city centres before and after the reconstruction based on their cadastral maps. Intelligibility is first measured as a configurational property of the street layout and then as a result of public participation in a navigation task using these maps and digital technology that records the speed of movement and trajectories. This allows a comparison between the original street layout and the new one, as well as across the different cities. Drawing on indicators of spatial cognition, this interdisciplinary research approach provides a means to measure and better understand the impact of the reconstruction on the intelligibility of urban environments.