Yksisuuntainen

Yksisuuntainen is a Finnish adjective meaning unidirectional or one-way. It describes something that is designed to or operates in a single direction, allowing movement or transmission only in that direction. The word is formed from the roots yksi (one) and suunta (direction) with the suffix -ainen, and its related noun form is yksisuuntaisuus, referring to the property of being unidirectional.

Common usages of yksisuuntainen appear across several domains. In road traffic, yksisuuntainen katu or yksisuuntaiset liikennemerkit designate streets where traffic is directed to move in only one direction to improve safety and flow. In electronics and physics, the term describes systems where signals or currents travel in one direction only; for example, diodes enable yksisuuntaista johtumista, allowing current to pass in one direction while blocking the opposite direction. In telecommunications and networking, yksisuuntaiset yhteydet refer to one-way communication channels or links, such as broadcast paths or downstream data connections.

The term is contrasts with kaksisuuntainen, meaning two-way or bidirectional, used for roads, communication channels, or processes that support movement or interaction in both directions. In everyday Finnish, yksisuuntainen is a practical descriptor for design choices that prioritize directional control, efficiency, or safety, and it appears in signage, policy discussions, and technical literature.