crossing gate; barrier
A mechanical barrier that blocks passage, typically at railway crossings, toll booths, or parking lot entrances/exits.
The railway crossing gate is down, so let's wait until the train passes.
駐車場の遮断機が開かなくて困った。
I had trouble because the parking lot barrier wouldn't open.
The crossing gate came down as the train approached.
The crossing gate rose after the train passed.
Several cars were waiting in front of the crossing gate.