Headlights, night driving and fog

Key points

1. Turn on your headlights any time you cannot clearly see at least 1,000 feet ahead.

   Source: Handbook p. 27

   “you must turn on your headlights anytime there is not enough light to clearly see at least 1,000 feet in front of your vehicle.”
   Maryland Driver's Manual, Handbook p. 27

2. Maryland law requires headlights when you use your wipers in bad weather.

   Source: Handbook p. 27

   “Maryland law requires that you turn on your headlights when using your windshield wipers in inclement weather.”
   Maryland Driver's Manual, Handbook p. 27

3. Switch to low beams at least 500 feet before meeting an oncoming vehicle.

   Source: Handbook p. 27

   “Change to low beams at least 500 feet before reaching vehicles coming toward you.”
   Maryland Driver's Manual, Handbook p. 27

4. Use low beams when following a vehicle 300 feet or less ahead.

   Source: Handbook p. 27

   “Change to low beams when following a vehicle that is 300 feet or less in front of you.”
   Maryland Driver's Manual, Handbook p. 27

5. At night, do not stare into the headlights of oncoming traffic.

   Source: Handbook p. 28

   “Do not stare into the headlights of traffic coming toward you in the opposite lane.”
   Maryland Driver's Manual, Handbook p. 28

6. In fog, when you see headlights or taillights ahead, slow down even more.

   Source: Handbook p. 28

   “When you see headlights or another vehicle's taillights ahead, reduce your speed even more.”
   Maryland Driver's Manual, Handbook p. 28

7. If fog is too thick to drive safely, pull completely off the road and turn on your flashers.

   Source: Handbook p. 28

   “pull completely off the road to a safe location and turn on your emergency flashers.”
   Maryland Driver's Manual, Handbook p. 28

8. In fog, use low beam headlights only, plus fog lights if you have them.

   Source: Handbook p. 28

   “Use low beam headlights only. Also use fog lights if you have them.”
   Maryland Driver's Manual, Handbook p. 28

Numbers to know

3 questions from the Maryland practice test

1. 1. When must a Maryland driver use headlights because visibility is limited?

   1. Only when visibility is below 100 feet
   2. When there is not enough light to clearly see at least 1,000 feet ahead
   3. Only during a snowstorm after stopping
   4. Only when driving on an interstate
   Show answer

   When there is not enough light to clearly see at least 1,000 feet ahead. The manual sets the visibility trigger at the point where there is not enough light to clearly see at least 1,000 feet in front of the vehicle. That includes situations such as fog and stormy weather, and it is not limited to interstates or to a 100-foot threshold. Turn on the headlights before visibility becomes dangerously short, not after the road disappears ahead.

2. 2. How far before an oncoming vehicle must a Maryland driver change from high beams to low beams?

   1. At least 100 feet
   2. At least 300 feet
   3. At least 500 feet
   4. Only after the vehicles pass
   Show answer

   At least 500 feet. When an oncoming vehicle is approaching, the driver must switch from high beams to low beams at least 500 feet before reaching that vehicle. Waiting until the vehicles pass can glare the other driver and reduce safety. The 300-foot figure applies to following a vehicle in front of you, so first identify whether the traffic is approaching or traveling in the same direction.

3. 3. When following another vehicle at night, when must Maryland drivers use low beams?

   1. Never, because the 500-foot rule covers every situation
   2. Only when the vehicle ahead taps its brakes
   3. At 500 feet after passing the vehicle
   4. When the vehicle ahead is 300 feet or less in front
   Show answer

   When the vehicle ahead is 300 feet or less in front. Maryland requires low beams when following a vehicle that is 300 feet or less ahead. This protects the driver in front from glare through mirrors. The 500-foot distance belongs to approaching traffic, not following traffic, and a brake tap is not the required signal. Classify the traffic relationship first, then apply the matching distance. The shorter following distance is the detail that separates these two headlight rules.

Source: the Maryland Driver's Manual, Section 5: Driving Situations and Conditions. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.