Headlights and Taillights All motor vehicles, with the exception of motorcycles, must have two white headlights that work on high and low beam, and red taillights that illuminate when the brake pedal is pressed. When set on high beam, headlights must make objects visible on the road ahead from at least 350 feet away. Replace damaged headlights. A cracked lens allows moisture and dust to accumulate inside the lamp, resulting in loss of illumination and increased glare for other motorists. Clean your headlights as often as you clean your windshield. Dirty headlights can reduce light output by as much as 75 percent. Have your headlights inspected at least once a year to make sure they are aimed properly. Some headlamps require an adapter or special settings. Refer to your operator’s manual for more information. Some vehicles have reduced-power headlights, called daytime running lamps, which turn on automatically when you drive during the daytime. These lights make your vehicle easier for others to see. Taillights and parking lights do not turn on automatically. Your headlights must be turned on at sunset and used until sunrise. They must also be used during weather conditions that include rain, snow, hail, sleet, or fog and any time you cannot clearly see the road ahead for a distance of at least 500 feet.