First, you should make sure both of your headlights are in good working order before driving your car. Headlights must be in use from sunset to sunrise.Secondly, headlights are also necessary when you cannot see more than 400 feet in front of you. You should also use your car's headlights whenever windshield wipers are in use.Thirdly, some studies have shown that when drivers elect to always drive with their headlights on it can reduce automobile accidents.