当可视距离不超过多少米的时候必须打开车辆头灯?You must turn your vehicle headlights on when visibility is less than:

当可视距离不超过多少米的时候必须打开车辆头灯?You must turn your vehicle headlights on when visibility is less than:
50米50 metres
100米100 metres
150米150 metres
200米200 metres

可视距离低于100米时务必打开车辆头灯,请牢记。