Fetching details from the dictionary...

opening (of a new road, railway, etc.); going into operation (e.g. telephone communication); beginning services
reopening (e.g. of a road to traffic); resumption of services
新しい高速道路が来月開通する予定だ。
The new highway is scheduled to open next month.
地下鉄の新路線が開通して便利になった。
The new subway line opened and became convenient.
開通したばかりの道路を走ってみた。
I tried driving on the newly opened road.