Runkolinjan

Runkolinjan is a term used in Finnish-language infrastructure planning to refer to a central or backbone line within a system. The compound derives from runko, meaning "frame" or "backbone," and linja, meaning "line." In practice, runkolinjan is used to describe the principal route, conduit, or service artery that supports secondary lines or feeders.

In telecommunications, runkolinja typically denotes the backbone fiber or cable network that carries long-distance and inter-regional traffic and connects major nodes. In transportation planning, the term may describe the primary corridor or spine of a transit network, such as a main railway or bus rapid transit line that other routes feed into. In energy and utilities, it can refer to the main feeder or trunk line within an electrical grid or distribution system, carrying the bulk of load or supply to sub-networks.

Because the term is context-specific, its exact scope and responsibilities vary by sector, company, and country. Users should refer to local standards or project documents to determine which facilities are designated as runkolinjan in a given setting.

See also: backbone network, trunk line, main line.