Criminal Offense of Failure to Use/Improper Use of Turn Signals, Headlights, and Emergency Flashers
In the exercise of its police power, a state may establish minimum equipment and usage standards for lighting equipment of motor vehicles, including headlamps, rear lighting, turn signals, and hazard warning lights.
As a general rule, state law requires drivers to use their headlights under the following circumstances:
- When a driver cannot see because of insufficient light on gray days or in heavy traffic when the vehicle may seem to blend in with the surroundings;
- When there are unfavorable atmospheric conditions, including rain, snow, sleet, hail, fog, smoke, or smog;
- When a driver cannot see pedestrians or vehicles on the highway for a distance of 1,000 feet ahead of the vehicle the driver is operating;
- Between sunset and sunrise;
- When driving through work zones.
Unauthorized or improper use of lights are also prohibited, such as driving with bright lights, failure to dim lights, glaring lights, driving with unauthorized or too many lights, and driving with improper lights to the rear.
In general, the driver of a standing or parked vehicle that may constitute a source of danger to others must use hazard lights to apprise others of the presence of the vehicle. A driver who is unable to maintain a speed of the minimum speed due to weather, grade, or other similar factors or is unable to maintain a speed consistent with the normal flow of traffic is required to use the hazard warning lights.
Motor vehicle must be equipped with signal lamps. In general, turning movements require signals to be given continuously during the last 100 feet traveled by a vehicle before turning. In some jurisdictions, if a driver is driving at 35 mph or more, the motorist must signal at least 300 feet before turning. If the vehicle's turn signals do not operate, the motorist must use hand signals. A number of jurisdictions require the use of signal lamps when changing lanes.
An improper use or failure to use lights is generally treated as a "summary" offense or traffic infraction, resulting in a fine and the assessment of driver demerit points. Fines and points are usually doubled in construction zones, however.