かいつう開通kaitsuu
1.

The process by which infrastructure such as roads, railways, or communication systems is completed and made available for public use.

2.

The initiation of operations for transportation or communication services, indicating that connections are now functioning and accessible.

3.

The act of establishing functional pathways or lines, allowing for travel or communication where there was none before.

Example:

橋は開通している。

かいつうしき開通式kaitsuushiki
1.

A ceremonial event marking the official start of operations for a newly constructed infrastructure, such as a railway, road, or bridge, often attended by dignitaries and the public.

2.

A formal gathering that celebrates the completion and readiness of a significant public project, typically featuring speeches, ribbon-cutting, and various festivities.

3.

An occasion that symbolizes the transition from construction to active use of a major transportation route or facility, highlighting its importance for community development and connectivity.

Example:

たくさんの人が新しい橋の開通式に参列した。