noun
widening (of a road)
Refers to the act or result of making a road wider. Often used in civil engineering and traffic contexts.
この道路の拡幅工事は来月から始まる。
The widening work on this road will start next month.
noun or participle which takes 'suru'
The verb form, typically used with する. Almost exclusively used for roads.
市は渋滞を減らすためにその道路を拡幅する計画だ。
The city plans to widen that road to reduce traffic congestion.