Yksisuuntaisten

Yksisuuntaisten is Finnish for “unidirectional” in its genitive plural form, used to describe multiple items that share a single direction of movement or flow. The base adjective is yksisuuntainen, and the related noun yksisuuntaisuus denotes unidirectionality. The form yksisuuntaisten appears in phrases such as yksisuuntaisten katujen (the one-way streets) or yksisuuntaisten liikennejärjestelmien (unidirectional traffic systems).

In road traffic design, unidirectional streets are used to reduce conflicts at intersections, increase street capacity, and simplify signaling, especially in dense urban areas. They require signage and road markings to guide drivers, cyclists, and pedestrians, such as “Yksisuuntainen liikenne” signs and directional arrows. Planning must balance access for residents, deliveries, and emergency services, and sometimes involves converting two-way sections to one-way to optimize network flow.

Beyond transportation, the term is also used in physics, information technology, and engineering to describe processes or systems that proceed in a single direction. Examples include unidirectional data flow in computing or unidirectional chemical or energy transfer where movement is favored or constrained to one direction by design or physical principles.

Etymology and grammar: the word is formed from the components yksi (one) and suunta (direction) with the suffix -inen to create an adjective; the plural genitive form is -isten, as in yksisuuntaisten katujen. This form enables construction of phrases that relate multiple unidirectional elements to another noun.