Stopping distance, bad weather and night driving

Key points

1. It takes an average of 1.5 seconds to perceive a threat and react to it.

   Source: Handbook p. 53

   “It takes an average of 1.5 seconds for a person to perceive a threat in the roadway and react to that threat.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 53

2. Allow at least a 3 second following distance in most driving situations.

   Source: Handbook p. 53

   “Allow at least a 3-second following distance for most driving situations.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 53

3. On slippery roads, double your following distance to 6 seconds or more.

   Source: Handbook p. 53

   “When driving on slippery roads, you should double your following distance to 6 seconds or more”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 53

4. In rain, slow down to increase your following distance to at least 6 seconds.

   Source: Handbook p. 55

   “You should slow down to increase the distance between your vehicle and the vehicle ahead to at least 6 seconds.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 55

5. Be extra careful in the first 30 minutes after rain begins, when oil and grime make the road slippery.

   Source: Handbook p. 55

   “Be extra careful during the 30 minutes after rain begins; grime and oil on the road surface mix with water and make the road slippery.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 55

6. At 50 mph in heavy rain your tires can lose all contact with the road; the best way to prevent hydroplaning is to slow down.

   Source: Handbook p. 55

   “at 50 mph your tires can lose all contact with the road. Under-inflated, worn, or bald tires lose contact with the road at much lower speeds. The best way to prevent hydroplaning is to slow down.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 55

7. Do not cross flooded washes.

   Source: Handbook p. 56

   “Heavy rain frequently causes “flash floods” in Arizona washes. Do not cross flooded washes.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 56

8. In a skid, turn the wheel quickly in the direction you want the vehicle to go.

   Source: Handbook p. 70

   “Turn the wheel quickly in the direction you want your vehicle to follow (in the direction of the skid).”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 70

9. Use high beams on highways only when no vehicle is coming toward you within 500 feet.

   Source: Handbook p. 57

   “Use high beams on highways when no other vehicle is coming toward you within 500 feet.”
   Arizona Driver License Manual and Customer Service Guide, Handbook p. 57

10. When following another car, use low beams within 200 feet.

    Source: Handbook p. 57

    “When following another car, use low beams whenever you are within 200 feet.”
    Arizona Driver License Manual and Customer Service Guide, Handbook p. 57

Numbers to know

3 questions from the Arizona practice test

1. 1. What following distance should you use in heavy rain?

   1. Exactly 3 seconds
   2. No more than 2 seconds
   3. The same gap used on dry pavement
   4. At least 6 seconds
   Show answer

   At least 6 seconds. During heavy rain, Arizona advises increasing the gap to at least six seconds. Water reduces visibility and traction, so the extra time helps you react if the vehicle ahead slows or a road hazard appears. Even in ordinary conditions the manual suggests a cushion of 3 to 6 seconds, so a 2 second gap or the usual dry pavement gap falls short here. Choose a fixed point on the road, count the interval after the lead vehicle passes it, and slow further when visibility or traction worsens.

2. 2. What is the best way to prevent hydroplaning in Arizona?

   1. Brake hard on wet pavement
   2. Slow down
   3. Accelerate across standing water
   4. Make rapid steering corrections
   Show answer

   Slow down. The manual identifies slowing down as the best way to prevent hydroplaning, which occurs when tires ride on a film of water and lose contact with the road. Braking hard can reduce control once traction is limited, and accelerating across standing water does not remove the water film. Rapid steering corrections can also create a skid. Reduce speed before reaching deep or flowing water, keep the wheel steady, and maintain tires in good condition with proper inflation and tread. If hydroplaning begins, do not brake and avoid steering changes until the tires grip again.

3. 3. When following another vehicle at night, at what distance must you switch from high beams to low beams?

   1. Within 100 feet
   2. Within 200 feet
   3. Only after the vehicle slows
   4. Within 300 feet
   Show answer

   Within 200 feet. Arizona requires low beams whenever your vehicle follows another car within 200 feet. The manual handles oncoming traffic separately: high beams are for highways when no vehicle is coming toward you within 500 feet, and you switch to low beams whenever you meet oncoming traffic to avoid blinding the other driver. The rule is about distance, not whether the car ahead slows, and 100 or 300 feet are not the stated figures. Make the change before the gap closes to 200 feet, then keep low beams on while you follow that closely.

Source: the Arizona Driver License Manual and Customer Service Guide, Section 5: Actively Avoiding Crashes. 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.