幹線

1. Origins, structure, and basic meaning

• Structure: 幹線(かんせん) is a principal route within a road, railway, or similar network.
• Basic usage: It describes a main road being temporarily closed because of an accident.
  • 事故の影響で幹線道路が一時通行止めになった。

2. Common pitfalls and similar expressions

• Main routes and branches
  • 支線(しせん) is a branch line extending from a main route. Its contrast with 幹線 concerns the route's role within the transport network.