crossing bar; boom barrier; toll bar
A horizontal bar that lowers to block passage, commonly seen at railway crossings, toll booths, and parking entrances.
When the crossing bar at the railway crossing comes down, cars must stop.
I waited for the boom barrier at the parking lot entrance to rise.
Compound of 遮断 (しゃだん, 'interruption, blocking') and 棒 (ぼう, 'bar, rod'). The term transparently describes a bar that blocks passage.