Megalopolis

A megalopolis is a large urban region formed when multiple metropolitan areas grow into a continuous, densely populated corridor with integrated economies and infrastructure. The term, combining Greek megas and polis, was popularized by urban geographer Jean Gottmann in 1961 to describe the northeastern United States strip from Boston to Washington, D.C., often called the BosWash corridor.

Megalopolises are characterized by high population and density, extensive transportation networks, economic interdependence among component cities, and shared urban systems for water, energy, and housing. They are usually polycentric, containing several major centers rather than a single capital city.

Notable examples include the Northeast Megalopolis in the United States, the Pearl River Delta and the Guangdong–Hong Kong–Macao Greater Bay Area in China, and the Tokyo–Yokohama–Nagoya corridor in Japan. In Europe, the Rhine-Ruhr and Île-de-France regions are sometimes discussed as megalopolises or as megalopolis-like zones.

Implications for planning and governance include the need for cross-jurisdiction coordination, regional planning, and investment in transportation, housing, and environmental sustainability. Challenges commonly cited are congestion, pollution, housing affordability, and resilience to climate risks.

The term is distinct from a single metropolis or simple conurbation, emphasizing continuous urbanization and functional integration across a broad area. Some analysts also use megaregion or urban corridor to describe related patterns.