Turn Signals in Japan: Turning (30 m) vs Changing Lanes (3 s)

Legal definitions and comparison table

Article 53(1) of the Road Traffic Act requires you to signal when turning left or right, making a U-turn, slowing down, stopping, reversing, or changing course while continuing in the same direction, and to keep signaling until the maneuver is finished. The timing and method are set by Cabinet Order (Enforcement Order Article 21).

The table in Enforcement Order Article 21 says: for left turns, right turns and U-turns, "when reaching the point 30 meters before the point of the maneuver (at an intersection, before the near edge of the intersection)"; for changing course in the same direction, "three seconds before the maneuver". The Rules of the Road say "about 3 seconds before".

Cancelling signals, and signals you must not give

Keep signaling until the maneuver is finished, then cancel promptly. You also must not signal for a maneuver you are not going to make (Article 53(4)). Leaving the indicator on after finishing a lane change is a violation.

Hand signals also exist. Japanese cars are right-hand drive, so for a left turn or move to the left: "extend the left arm horizontally out of the left side" or "put the right arm out of the right side and bend the elbow straight up"; for a right turn, U-turn or move to the right: "extend the right arm horizontally out of the right side" or "put the left arm out of the left side and bend the elbow straight up". The Rules of the Road recommend adding hand signals when the indicator is hard to see, for example in low evening sun.

Signals for slowing down, stopping and reversing are given at the moment you are about to do so (brake lights, reversing lights and so on).

When you may not change lanes even after signaling

A signal is only one condition for changing lanes. Article 26-2(2) says you must not change course if it is likely to make a vehicle coming from behind suddenly change speed or direction. Signaling does not give you the right to cut in.

Conversely, when a car ahead signals that it is moving to the left edge, center or right edge of the road to turn, the car behind must not obstruct that move unless it would have to change its own speed or direction suddenly (Article 34(6)).

Also, where lanes are divided by a yellow line, you must not cross that line to change lanes (Rules of the Road).

At roundabouts, no signal when entering

Roundabouts (環状交差点) have their own signal rules (Article 53(2); Enforcement Order Article 21(2)). No signal is needed when entering; you give a left signal when leaving.

The time to signal for leaving is when you pass the exit just before the one you will take (if you leave at the first exit after entering, when you enter the roundabout). It is neither 30 meters nor 3 seconds, so do not mix them up.

Tricky test questions and answers

These question types appear on the knowledge test. They swap the numbers (30 m, 3 s) and the maneuvers.

Example 1: "進路を変えようとするときは、その30メートル手前で合図をしなければならない。" (When changing course, you must signal 30 meters before.) Answer: False (×). A lane change is about 3 seconds before; 30 meters is for turns and U-turns.

Example 2: "転回しようとするときの合図は、転回しようとする地点の3秒前に行う。" (Signal a U-turn 3 seconds before the point of the U-turn.) Answer: False (×). Like turns, a U-turn is signaled 30 meters before.

Example 3: "進路変更の合図は、進路を変えようとする約3秒前に行い、進路変更が終わるまで続けなければならない。" (Signal a lane change about 3 seconds before and keep signaling until it is finished.) Answer: True (○).

Example 4: "方向指示器で合図をすれば、後続車との距離が近くても進路変更することができる。" (Once you signal with the indicator, you may change course even if a following car is close.) Answer: False (×). A lane change that forces a following car to brake or swerve suddenly is prohibited.

Example 5: "環状交差点（ラウンドアバウト）に入ろうとするときは、あらかじめ合図を出さなければならない。" (You must signal in advance when entering a roundabout.) Answer: False (×). No signal on entry; signal when leaving.

Practice signal questions in your language

Unless you pair 30 meters and 3 seconds with the right maneuver, you will hesitate on test day. menkyopass's license conversion (外免切替) drill lets you practice signal and intersection questions with explanations in Vietnamese, English, Chinese and Japanese (the first mock test and 3 topics are free; all questions are a one-time ¥2,980).

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

Related guides

• Japan Traffic Light Rules: Yellow, Flashing, Arrows, Signals
• Overtaking Rules in Japan: No-Overtaking Zones and Passing
• What does 環状交差点 (kanjō kōsaten) mean? Roundabouts in Japan
• What does 二段階右折 (nidankai usetsu) mean? Two-step right turn
• 追越し vs 追抜き: Overtaking vs Passing in Japan's Test

Sources (in Japanese)

• e-Gov法令検索「道路交通法」（第26条の2、第34条第6項、第53条）
• e-Gov法令検索「道路交通法施行令」（第21条）
• 警察庁「交通の方法に関する教則」（第3章第5節 進路変更など）