Extension or elongation; lengthening or stretching of something (e.g., roads, railway lines, materials).
高速道路を市街地まで延伸する計画が発表された。
A plan was announced to extend the expressway into the urban area.
鉄道の路線延伸によって、周辺の開発が進んだ。
The extension of the railway line promoted development in the surrounding area.