Updated · Checked against the California Driver’s Handbook, the California Vehicle Code (CVC) and the DMV drive-test criteria (DL 955).

Lesson 38 of 38 · California traffic rules

High beams Dim them for others: 500 and 300 feet

The rule

At night on a dark road, use your high beams when nobody is coming toward you. Dim them to low beams within 500 feet of a vehicle coming toward you and within 300 feet of a vehicle you follow.

CVC 24409 · CA Driver's Handbook, "Using Your Headlights" and "Darkness"
In short

When do you have to dim your high beams in California?

Within 500 feet of a vehicle coming toward you, and 300 feet of a vehicle you follow (CVC 24409).

Why this rule exists

High beams light the road much farther ahead, so you see people and animals at the side of the road in time. Into another driver's eyes, or into their mirrors, they blind them for a moment.

Step by step on the road

  1. At night on open country roads or dark city streets, use your high beams when nobody is close.
  2. Drive so you can stop within the distance your headlights light up.
  3. Dim to low beams as soon as you see headlights coming toward you, before they are within 500 feet.
  4. Dim when you come within 300 feet of a car ahead of you.
  5. Switch the high beams back on once the other car has passed.
  6. If an oncoming driver keeps the high beams on, look toward the right edge of your lane, and do not answer with your own high beams.

Common mistakes

  • Forgetting to dim for the car ahead: your high beams blind its driver through the mirrors.
  • Dimming too late, when the other car is already close.
  • Using high beams in fog, where they reflect back and cause glare.

On the DMV drive test

Before the drive, the examiner asks you to find the headlight switch (DL 955 pre-drive item 14). On the drive, not using the headlights when darkness requires them is a critical driving error.

Based on the DMV’s Driving Test Criteria (DL 955) and its score sheet (DL 32). How the drive test works ›

Questions people ask

Is it illegal to drive with high beams on in California?

No, high beams are fine when nobody is close. You must dim them within 500 feet of an oncoming vehicle and within 300 feet of a vehicle you follow (CVC 24409).

Should you use high beams in fog?

No. In fog, high beams reflect back and cause glare. Use your low beams (Handbook).

What should you do if an oncoming car does not dim its high beams?

Do not look into the lights. Look toward the right edge of your lane, and do not answer with your own high beams (Handbook).

Test yourself

Kees' three questions on this rule, the “Did you know?” facts and his tip come with the drive, in Voorrah! Pro.

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