interregional

Interregional is an adjective describing something that involves, relates to, or occurs between regions. In geography, regional science, economics, and public policy, the term is used to describe exchanges, relationships, or planning efforts that span more than one region, whether within a country or across national borders. It is contrasted with intraregional, which concerns activity confined to a single region.

Interregional flows include trade, investment, migration, information, and transportation networks that link different regions. In economics, interregional analysis uses models that trace how production, employment, and demand in one region affect others. In planning, interregional approaches coordinate infrastructure, environmental management, and development strategies across regional boundaries to improve efficiency and reduce disparities.

Examples and institutions: Interregional trade and travel link major urban and rural regions. Public programs such as the European Union's INTERREG funds support interregional cooperation by financing projects that involve cross-border, transnational, or interregional collaborations. Interregional transport corridors, such as highways and rail lines that connect cities across regions, are common policy targets to enhance connectivity.

Challenges include governance fragmentation, differing regulatory regimes, and data comparability across regions. Successful interregional work often requires formal agreements, data harmonization, and mechanisms for joint decision-making to manage shared infrastructure, environmental, or economic objectives.