When Headlights Are Required in Arizona: Law & Safety

Arizona law (ARS §28-922) mandates headlight use during two conditions:

1. Time-Based: Sunset to Sunrise

• Mandatory: From sunset to sunrise (civil twilight not sufficient)
• Practical tip: Turn on 30 min before sunset / keep on 30 min after sunrise

2. Visibility-Based: "When Visibility Is Significantly Reduced"

• Conditions: Heavy rain, snow, fog, dust storms (haboobs), smoke, blowing sand
• Standard: When persons/vehicles not clearly discernible at 500 feet
• Common triggers: Monsoon downpours, haboobs (Phoenix/Yuma), wildfire smoke, winter fog (Flagstaff)

Additional Requirements

• High beams: Dim within 500 ft of oncoming, 200 ft following
• Parking lights: Not a substitute for headlights when driving
• Daytime running lights (DRL): Satisfy requirement if vehicle so equipped (post-1990s most)
• Motorcycles: Headlight always on (modulating permitted)

Penalties

• Civil traffic violation: ~$100–$150 + points (varies by jurisdiction)
• Contributing factor: In crashes, failure to use lights = negligence per se

Safety Best Practice

"Wipers on → Lights on" — Arizona doesn't mandate this by statute (unlike 20+ states), but it's the smart habit. In monsoon dust/rain, low beams + fog lights (if equipped) reduce glare-back.

Simple rule: If you need wipers, you need headlights.