Changing lanes Signal, mirror, shoulder check
Before changing lanes: signal, check your mirrors, look over your shoulder in the direction you move, and move only into a gap that is big enough. Stay in one lane otherwise.
CVC 21658(a) · CVC 22107 (signal) · CA Driver's Handbook, "Changing Lanes" · DMV DL 955 (no shoulder check: critical error)How do you change lanes safely in California?
Signal, check your mirrors, look over your shoulder in the direction you move, and move only into a gap that is big enough (Handbook, "Changing Lanes"; CVC 21658(a)).
Why this rule exists
Your mirrors leave blind spots beside the rear of the car. Only a quick look over the shoulder shows the car or motorcycle sitting there.
Step by step on the road
- Signal in the direction you want to move.
- Check your mirrors for traffic behind and beside you.
- Look quickly over your shoulder into the blind spot on that side, then eyes ahead again.
- Move over smoothly, only into a gap big enough for your car. If a car is passing you in that lane, let it go by first.
- Keep up with the traffic: you do not need to slow down. Cancel the signal afterwards.
Common mistakes
- Checking only the mirrors and not the blind spot.
- Signaling and moving at the same moment.
- Braking before the lane change.
- Leaving the signal on afterwards.
On the DMV drive test
The DL 32 sheet marks each lane change for traffic check, signal, speed, spacing and steering control. For a lane change to the right, DL 955 wants you to check your right-hand mirror and look over your right shoulder (the left ones for a change to the left), signal before and cancel after, wait for an adequate gap and end in the center of the lane. It is not necessary to slow down. Not checking your mirrors or over your shoulder when changing lanes 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
Do you have to signal to change lanes in California?
Yes. CVC 22107 requires a signal before you move right or left when another vehicle may be affected, and the Handbook says to always signal when you change lanes.
What is a blind spot?
The area beside the rear of your car that your mirrors do not show. Only a quick look over your shoulder shows a car or motorcycle there.
Do you need to slow down to change lanes?
No. The Handbook and the DMV test criteria say it is not necessary to slow down before a lane change: keep up with the traffic and use the gap.
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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