拡幅

1. Origins, structure, and basic meaning

• Structure: 拡幅, read かくふく, is the noun widening and the stem of 拡幅する, to widen.
• Basic usage: 歩道の拡幅に合わせる treats widening as a project, whereas 橋を拡幅する predicates the action performed on a bridge.

2. Common pitfalls and similar expressions

• Nominal 拡幅 and verbal 拡幅する
  • 拡幅に refers to the widening project as a noun; 拡幅する takes 橋を as the object of the action.