Gaimen50-question practice tests in the real exam formatWhat does 合図 (aizu) mean? Signals: 30 m before, 3 seconds before
Updated: 2026-10
合図 (あいず, aizu) means signaling to others with indicators, brake lights or your hand when turning, making a U-turn, changing lanes, slowing, stopping or reversing. Timing basics: turns and U-turns '30 m before the point', lane changes 'about 3 seconds before', slowing, stopping and reversing 'when you are about to do it'. Keep signaling until done, then stop. Tests love to swap the distance (30 m) and the time (3 seconds).
Legal meaning
Article 53(1) of the Road Traffic Act (道路交通法) requires drivers (except of light vehicles other than bicycles) to signal by hand, indicator or lights when turning left or right, making a U-turn, slowing, stopping, reversing, or changing course while traveling in the same direction, and to keep signaling until the maneuver is complete. Timing and method are set by Enforcement Order Article 21.
Under Article 53(4), you must stop signaling once done, and must not signal a maneuver you are not going to make.
Timing and method at a glance
For turns at an intersection, '30 m before' is measured from the near edge of the intersection.
| Maneuver | When | How |
|---|---|---|
| Left turn | 30 m before the point (at intersections, before its near edge) | Left indicator, or left arm out horizontally / right arm bent up at the elbow |
| Move left (lane change) | About 3 seconds before | Same |
| Right turn, U-turn | 30 m before the point (at intersections, before its near edge) | Right indicator, or right arm out horizontally / left arm bent up at the elbow |
| Move right (lane change) | About 3 seconds before | Same |
| Slow down, stop | When about to do it | Brake lights, or arm extended diagonally downward |
| Reverse | When about to do it | Reversing lights, or arm diagonally down, palm backward, moving back and forth |
Signals at roundabouts
You do not signal when entering a roundabout (環状交差点). You signal when exiting, and when slowing, stopping or reversing inside (Art. 53(2)). Signal your exit as you pass the exit before the one you will take (or as you enter, if leaving by the first exit), in the same way as a left turn (Enforcement Order Art. 21(2)).
Rules for signaling vehicles and those who see them
A signal is not permission. Even with your indicator on, you may not change lanes if a vehicle behind would have to brake or swerve suddenly.
Conversely, when a vehicle ahead signals to move to the left edge, center or right edge to turn, vehicles behind must not obstruct it unless that would require a sudden change of speed or direction (Art. 34(6)). The same applies to a route bus signaling to pull out from a stop (Art. 31-2).
How it appears on the test, and the traps
Memory tip: U-turns belong with right turns (30 m); only lane changes use time (3 seconds).
- 'When turning right or left, signal 30 m before the point' → True
- 'Signal a U-turn 3 seconds before' → False (30 m before)
- 'Signal a lane change 30 m before' → False (about 3 seconds before)
- 'Keep the lane-change signal on until the change is complete' → True
- 'With your indicator on, you may change lanes even if the car behind is close' → False
Practice questions using this term
- When turning right or left, you must give the signal 30 meters before the point where you will turn.
- You must signal about three seconds before making a U-turn.
- When you are about to enter a roundabout, you must give a signal in advance.
- When a route bus at a bus stop signals that it is about to pull out, vehicles behind it must give way in every case.
- When you are about to change course (change lanes), you must give a signal 30 meters before doing so.
- The signal for changing course must be given about 3 seconds beforehand and continued until the change of course is complete.
- As long as you signal with your turn indicators, you may change course even when the vehicle behind you is close.
FAQ
Q. When do I signal a turn?
A. 30 m before the turning point; at an intersection, 30 m before its near edge.
Q. When do I signal a lane change?
A. About 3 seconds before changing lanes.
Q. Are hand signals allowed?
A. Yes, the law allows them. Left turn: left arm out horizontally or right arm bent up; right turn: right arm out horizontally or left arm bent up.