driving signal

例句：

1. 1. The driver needs to be aware of the driving signal when changing lanes.
   司机在变道时需要留意行驶信号。
2. 2. The traffic police are using a red light as a driving signal.
   交通警察正在使用红灯作为行驶信号。
3. 3. The car's engine is producing a loud noise, which is a warning signal for the driver.
   汽车发动机发出噪音，这是对驾驶员的警告信号。