Why did some factories move from the Keihin Industrial Zone to Chiba and Ibaraki prefectures?

The relocation of factories from the Keihin Industrial Zone to Chiba and Ibaraki prefectures was primarily driven by the severe challenges resulting from the region's rapid postwar industrial growth.1

Key factors necessitating this industrial decentralization included:

• Land Shortage: Despite extensive land-reclamation projects in Tokyo Bay, the central Keihin zone faced a persistent lack of space for further industrial expansion.1
• Overcrowding: The intense concentration of heavy industry in the Kawasaki-Yokohama area led to significant overcrowding.1
• Environmental and Infrastructure Concerns: The region struggled with environmental pollution and inadequate transportation infrastructure, which hindered efficient operations.1

As a result, many heavy industries—including iron, steel, chemical, and shipbuilding sectors—migrated to coastal areas in Chiba and Ibaraki, where deepwater ports and large tracts of reclaimed land were available to support continued growth.12