Under what condition should headlights be turned on in a commercial vehicle?

Headlights should be turned on in a commercial vehicle whenever visibility is reduced. This includes conditions such as rain, fog, snow, or any situation where it is difficult to see other vehicles or objects on the road. The primary purpose of headlights is to improve visibility for both the driver and others on the road. By using headlights in reduced visibility conditions, drivers can enhance their ability to see and be seen, thereby increasing safety.

While using headlights only at night may seem sufficient, there are many situations during the day, such as overcast weather or rain, where visibility can be compromised. Similarly, although it may seem logical to turn on headlights during bad weather, they should also be used during other times when visibility is poor, not just in extreme conditions. In bright daylight, while it may not be strictly necessary, it is still important to ensure that headlights are functioning correctly and can be utilized when conditions warrant them.