pääreittiin

Pääreittiin is the illative singular form of the Finnish noun pääreitti, meaning the main route or principal transport corridor. The illative case marks movement toward or entry into something, so pääreittiin literally means into the main route. The term is primarily used in technical or planning contexts, but can also appear in road signage, transport schedules, or map labels to indicate the route that serves as the primary artery within a network.

Etymology: pitkä koostuu pää- ('main' or 'head') and reitti ('route'). The illative suffix -iin attaches to the noun to indicate direction toward the route, producing pääreittiin.

Usage: In Finland, pääreittiin can describe entering a main arterial path in road or rail networks, or directing traffic and pedestrians toward the primary route in signage and planning documents. It can also appear in hiking or cycling networks to indicate moving onto the principal trail when multiple routes exist.

Examples: Siirryimme pääreittiin. Kulkijoita ohjataan pysymään pääreitillä, jotta liikenne sujuu tehokkaasti. In these contexts, the term helps specify that attention or movement should switch to the main route rather than secondary paths.

See also: pääreitti, illatiivi.