A traffic light or traffic signal device installed on roads to control vehicle and pedestrian movement.
交差点の信号機が赤になったので止まってください。
The traffic light at the intersection turned red, so please stop.
信号機の故障で交通が混乱している。
Traffic is chaotic due to a traffic light failure.
自転車は歩道の信号機に従って渡ってください。
Cyclists should cross following the pedestrian traffic light.
A signaling apparatus in general; any device that emits signals (used also in industrial or communications contexts).
工場の入り口に警報用の信号機を設置した。
A signal device for alarms was installed at the factory entrance.
鉄道では信号機が安全運行の要となる。
In railways, signaling equipment is key to safe operations.