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California following-distance and scanning rules

Looking far enough ahead and leaving room buys the seconds you need when something goes wrong. That’s the whole idea behind following-distance rules.

Checked Oct 11, 2026 · official sources linked

9 rules · 9 written-test points

Key points, in our words

The idea behind it

Roadfeel’s road-sense principles

  • See and be seen You can’t avoid what you don’t see, and others can’t avoid you if they can’t see you. Scan far ahead, check blind spots, and use your lights.
  • Speed eats up your reaction time Every extra mph covers more ground before you even touch the brake, and braking distance grows much faster than speed. Speed rules buy you time.

All the rules, in our words

Tags show the kind of rule and whether it’s a written-test point or matters on the drive test (our tagging). Each rule links to its official source.

  1. Keep your eyes moving and scan at least 10 seconds ahead so you have time to react and avoid last-second moves.

    Safety advice Written test · Drive test California Driver Handbook: Safe Driving

  2. Three-second rule: when the car ahead passes a fixed point, count three seconds. If you reach the point before you finish counting, you’re following too closely.

    New York differs: Two-second rule: when the car ahead passes a fixed object such as a sign or overpass, count ‘one thousand one, one thousand two.’ If you reach the object before you finish, you’re following too closely. New York rule

    Safety advice Written test · Drive test California Driver Handbook: Glossary

  3. Tailgating blocks your view ahead and leaves no time to react if the car in front brakes hard. If someone cuts in close, ease off the gas to rebuild space.

    Safety advice Written test California Driver Handbook: Safe Driving

  4. If a tailgater is behind you, keep your course and speed, then move right when it’s safe so they can pass.

    Safety advice Written test California Driver Handbook: Safe Driving

  5. Don’t linger in another driver’s blind spot or right alongside other cars, keep space from parked vehicles, and look both ways even when cross traffic faces a red light or stop sign.

    Safety advice Written test · Drive test California Driver Handbook: Safe Driving

  6. Blind spots are the areas beside and slightly behind you that mirrors don’t show. Check them by turning your head, not your body or the wheel, to look over your shoulder.

    Safety advice Written test · Drive test California Driver Handbook: Safe Driving

  7. Do a shoulder check before you change lanes, turn, merge, back up, pull out of a parking space or from the curb, parallel park, or open your door.

    Safety advice Written test · Drive test California Driver Handbook: Safe Driving

  8. Check behind you often with your mirrors, especially before slowing down, changing lanes, turning into a driveway, pulling over, or backing up, to avoid being rear-ended.

    Safety advice Written test · Drive test California Driver Handbook: Safe Driving

  9. With hazards on both sides, such as an oncoming car and a cyclist, handle one at a time: slow down, let the car pass, then give the cyclist at least 3 feet.

    Safety advice Written test California Driver Handbook: Safe Driving (cont. 2)

Practice this chapter in the app · FreeYour space cushion3-second rule, scanning 10 seconds ahead6 min · InteractiveStart this lesson

Sample questions

3 of our 18 practice questions for this chapter, with explanations. The rest are in the app.

Sample question 1/3

How do you use the three-second rule?

  1. When the car ahead passes a fixed point, count three seconds; if you reach the point first, you’re too close
  2. Count three seconds after the light turns green before you go
  3. Keep three car lengths between you and the car ahead
  4. Check your mirrors every three seconds
Show answer

Answer: A. When the car ahead passes a fixed point, count three seconds; if you reach the point first, you’re too close

Pick a sign the car ahead passes and count three seconds; that gap gives you time to react if it brakes suddenly. Reach the sign before you finish? You’re following too closely.

California Driver Handbook: Glossary

Sample question 2/3 Common mistake

Which pair of numbers matches the handbook’s habits for watching the road ahead and following other cars?

  1. Look 3 seconds ahead; follow 10 seconds back
  2. Look 5 seconds ahead; follow 5 seconds back
  3. Look 10 seconds ahead; follow 1 second back
  4. Look 10 seconds ahead; follow 3 seconds back
Show answer

Answer: D. Look 10 seconds ahead; follow 3 seconds back

Look at least 10 seconds down the road so you have time to react. Use the three-second rule to stay at least 3 seconds behind the car in front. Swapping the two numbers is a common mix-up.

California Driver Handbook: Safe Driving

Sample question 3/3

How should you check your blind spots before changing lanes?

  1. Use only your side mirrors; turning your head is unsafe
  2. Look over your shoulder out the side window, turning only your head
  3. Turn your whole body around and look out the rear window
  4. Adjust your mirrors so you never need to check blind spots
Show answer

Answer: B. Look over your shoulder out the side window, turning only your head

Check your blind spots by turning only your head and looking over your shoulder out the side windows. Don’t turn your body or the steering wheel, so the car doesn’t drift out of its lane. Every vehicle has blind spots that mirrors don’t show, usually at the sides slightly behind the driver.

California Driver Handbook: Safe Driving

15 more practice questions for this chapterKeep practicing in Roadfeel

Sources

Restated in our own words from the California Driver Handbook (DL 600, rev. 6/2025) and dmv.ca.gov. The handbook is licensed CC BY-NC 4.0, which bars commercial reuse, so we don’t reproduce it; we quote short phrases and link to it.

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