The Ruhr Valley, which developed less from historically grown cities than from huge industrial settlements, was especially hard hit by processes of deindustrialization after World War II. Beginning in the mid-1950s, employment in the mining industry fell drastically; many mines closed, and in some cities of the Ruhr Valley unemployment reached 20 percent. As a result, to manage the structural transformation, the German state launched initiatives whose extent and duration were unique in the world. In the early 1960s, measures still banked on promoting the old industries, but a little later an active transformation policy began with the expansion of the educational system and the tertiary sector. In the following decades, this was consistently continued with technological and cultural projects. In the meantime, the service sector has replaced industrial production as the dominant economic branch. But the loss of population remains a challenge for the region.
By today, the Ruhr Valley has lost about 10 percent of its inhabitants, despite immigration. Some cities have even lost 30 percent. It is assumed that the population will continue to decline for the next 20 years – in some communities by as much as another 15 percent. Until now, the disuse of industrial facilities was the biggest challenge to urban planning, but in the future untenanted residential areas will become acute. It is still unclear whether the Ruhr Valley will remain a contiguous conurbation after the end of the industrial age, or whether the cities and communities will tend to orient themselves toward the exterior – for example, Duisburg toward the Lower Rhine region and Dortmund toward the Sauerland.