megaregion

A megaregion is a large network of metropolitan areas whose economies and daily life are closely linked through labor markets, supply chains, and shared infrastructure. The concept emphasizes functional connections—such as commuting patterns, trade flows, and transportation networks—across a broad geographic area, often crossing political boundaries. Megaregions are typically polycentric, containing multiple cities and substantial urbanized spaces that together generate a large combined economic footprint.

Key characteristics include high population and employment levels, extensive intercity transportation corridors (highways, rail, ports, and airports), interconnected housing and energy systems, and overlapping environmental and resource management needs. They arise from sustained urban growth and globalization, and are used in planning to address competitiveness, infrastructure needs, housing, and sustainability at a scale larger than single cities or metro areas.

Governance and planning considerations are central to megaregions. Effective planning often requires cross-jurisdiction collaboration, shared data, and coordinated investments in transportation, housing, water, and energy infrastructure. Challenges include funding, political coordination across borders or states, and balancing growth with environmental and social equity. Critics argue that the term can be vague or overemphasize economic linkages at the expense of smaller communities and rural areas.

Examples commonly cited in policy and planning discussions include the Northeast Megaregion (Bos-Wash corridor) in the United States, the Great Lakes Megaregion, and the Southern California megaregion. In Europe and other regions, densely connected clusters such as the Randstad or Tokyo–Osaka areas are sometimes described as megaregions depending on the framing and methodology used.