red light, red signal
あいつ、赤信号で渡ったぞ。
That guy just crossed against the light.
君は赤信号を無視して走りましたね。
You ran the red light, didn't you?
赤信号の時に横断してはいけないと警官は私たちに言いました。
The police officer told us not to cross when the light is red.
彼は赤信号にも車を止めなかった。
He didn't stop the car even when the light was red.
赤信号で通りを渡るのは危険だ。
Crossing the street against a red light is dangerous.