Rush hour — the time period when public transport and roads are particularly crowded (e.g., commuting times).
ラッシュ時は電車が非常に混むので早めに家を出た方がいい。
Trains are extremely crowded at rush hour, so it's better to leave home early.
この路線は朝のラッシュ時に遅延が出やすい。
This line tends to experience delays during the morning rush hour.
ラッシュ時を避けて出社する工夫をしている。
I'm trying to avoid rush hour when going to work.