Overtaking and Lane Rules in Japan: Where It Is Banned, and How

What counts as "overtaking" in Japan?

Overtaking has a legal definition with three parts: you catch up with the vehicle ahead, you change course, and you pass alongside it and move out in front. That is Art. 2(21) of the Road Traffic Act (the definition), and the middle part is what makes it a definition rather than a description.

If you pass a vehicle without changing course — for example it is in the next lane and you simply keep going — that is not 追越し but 追い抜き oinuki, 'passing'. The distinction decides several questions, because some rules cover only overtaking while others cover both. The 30-metre zone before a pedestrian or bicycle crossing bans both overtaking and passing (both are banned) — and note that the figure there is 30 m, not 50 m. If the vocabulary is what is tripping you up, the oikoshi entry in the glossary has the term on its own page.

Which side do I pass on?

On the right, as a rule. Art. 28(1) states that a vehicle overtaking another must pass on the right side of the vehicle being overtaken (pass on the right). Japan drives on the left, so the passing side is the right — the mirror image of what many drivers arrive with, which is why 'you must pass on the left' is false and 'the right lane was busy so I passed on the left' is also wrong.

Two situations reverse it. You pass on the left when the vehicle ahead has pulled over towards the centre of the road (or the right edge on a one-way street) in order to turn right, and when you are overtaking a streetcar (both left-side exceptions). Streetcars run on tracks laid in the road, so passing one on its right would put you in the oncoming half — hence 'you pass a streetcar on its right' is false. Throughout the manoeuvre you must keep a safe lateral gap, and you must watch not only oncoming and following traffic but also what is happening in front of the car you are passing.

Where is overtaking prohibited?

Six places, and the numbers matter. The Rules of the Road list them together: where a no-overtaking sign is posted; near a corner or bend; near the crest of an uphill and on a steep downhill; in a tunnel (except a tunnel that has marked traffic lanes); at an intersection and within 30 m before it, unless you are travelling on a priority road; and at a railway crossing, pedestrian crossing or bicycle crossing and within 30 m before it (the full list).

The test attacks each item by changing one word. Corners and bends are banned even when no oncoming vehicle is in sight (still banned) — visibility is not the test, the location is. A steep downhill is banned just like the crest of a climb, so 'the crest is banned but a steep downhill is fine' is false. Tunnels are banned unless the tunnel has marked lanes, so 'always banned in a tunnel' is false. At intersections it is 30 m with a priority-road exception (30 m, priority road excepted); at crossings it is 30 m with no 10-metre version. Separately, you may not overtake a vehicle that is itself overtaking — 'double overtaking' (never) — nor cut in front of a vehicle that has stopped or slowed at an intersection or railway crossing (no cutting in).

What do the two no-overtaking signs mean?

They are different signs with different scopes, and confusing them is the single most common error in this topic. The sign called 'no overtaking by crossing into the right half of the road' (追越しのための右側部分はみ出し通行禁止, No. 314 in the Sign Order) bans only the act of crossing into the oncoming half in order to overtake (what it bans). Overtaking that stays inside your own half of the road remains permitted, so 'this sign bans overtaking that does not cross the centre' is false. The outright ban is a different sign — 'No Overtaking', which carries an additional plate reading 追越し禁止 beneath the same disc — and that one bans overtaking itself. Same picture, extra plate, much wider ban: check for the plate before you decide.

Why does the 'crossing' version exist at all? Because crossing into the right half to overtake is sometimes lawful without it. Art. 17(5)(iv) allows you to cross into the right half in order to overtake where the left half of the road is less than 6 metres wide and visibility is good — the threshold is 6 m, not 8 m — and the sign is what switches that permission off (the 6-metre rule). The same distinction applies to the painted version of the sign as a road marking (marking, not a total ban).

Which lane should I be in? Keep left, yellow lines, straddling

The default is the first lane counting from the left edge of the road (Art. 20) (first from the left) — not the second (not the second). With two lanes in one direction you use the left one; with three or more you keep the rightmost free for overtaking and use the others (leave the rightmost free). On a road with no marked lanes you keep to the left side of the road except where it is unavoidable, such as when overtaking (keep left).

When you do overtake on a laned road, you use the lane immediately to the right of your own — not two lanes across, and certainly not the one to your left (immediately right) — and once you are past you must return promptly to a lane other than the rightmost (return promptly). Sitting in the rightmost lane afterwards invites speeding and short following distances, which is why the rule is written as a duty.

Three lane-marking rules complete the picture. You may not cross a yellow lane line to change lanes (yellow means no) — and where a 'no lane change' marking is drawn, it may restrict only one direction, so read which side the line is on. You may not straddle two lanes or drift out of your lane (no straddling), and you may not change lanes repeatedly without reason. Finally, when a faster vehicle catches you up: you must not speed up until it has finished passing (do not accelerate), and on a road without lanes you must pull as far left as possible to let it by if there is not enough room (yield left) — a duty that does not apply on a laned road, where the other driver can simply use another lane.

Turning: do I have to move into the nearest lane first?

Yes — and for a left turn the law is unusually specific. Art. 34(1) requires you to move as close as possible to the left edge of the road in advance, and then proceed slowly (徐行 jokō — slowly enough to stop immediately) along that left edge (left-turn method). Both halves are required: moving over beforehand, and hugging the edge through the turn. Moving to the centre and cutting inside the intersection is the wrong shape entirely.

A right turn is the mirror image with one twist. You move as close as possible to the centre of the road in advance and pass slowly just inside the centre point of the intersection — just inside, not outside. On a one-way street there is no oncoming traffic to leave room for, so you move to the right edge instead of the centre.

Mopeds are a separate case. At a signal-controlled intersection on a road with three or more lanes — the threshold is three, not two — or wherever the 'two-stage right turn for mopeds' sign is posted (the sign), a general moped must make a two-stage right turn (二段階右折): keep to the left edge, signal on reaching the point 30 m before the intersection — 30 m, not 50 — go straight across on green, stop at the far side, turn to face right, and wait for the signal ahead to go green. In that situation the green right-turn arrow does not help you: a moped required to turn in two stages may not turn on it. The two-stage right turn glossary entry covers the manoeuvre on its own page.

When can I drive in a tramway (kidōshiki)?

Almost never along it — only across it. Art. 21(1) prohibits driving within the tramway strip (軌道敷 kidōshiki, the part of the road carrying the streetcar tracks) except when you are crossing it to turn left, turn right, cross the road or make a U-turn, or where it is unavoidable in order to prevent danger (the general ban, crossing to turn is fine).

There are further exceptions, and the visible one is a sign: 'Vehicles may use the streetcar track area' (軌道敷内通行可, No. 402) permits motor vehicles to travel in the strip (the sign) — it does not permit parking there. Even with the sign, two duties survive: you must not obstruct the streetcar (never obstruct it), and if one approaches from behind you must promptly leave the strip or keep the necessary distance from it (leave promptly) — promptly leaving, not stopping where you are.

There is a reason streetcars get their own rules rather than being folded into the traffic. Under Art. 2(8), a 'vehicle' (車両) means a car, a moped, a light vehicle or a trolleybus — a streetcar is not a 車両 at all (it is not included). Whenever a question mixes streetcars and vehicles, check which of the two words it is using.

FAQ

What does the "no overtaking" sign mean, and how is it different from the other one?

The "No Overtaking" sign bans overtaking itself. The similar-looking "no overtaking by crossing into the right half of the road" sign bans only crossing into the oncoming half in order to overtake — overtaking that stays inside your own half is still allowed where that sign is posted.

When is it allowed to overtake on a curve?

Never. Corners and bends are places where overtaking is prohibited, and the ban applies even when no oncoming vehicle is in sight. The same applies near the crest of an uphill slope and on a steep downhill.

You want to overtake — what is the right thing to do?

Confirm it is not a no-overtaking place, check ahead and check to your right and right rear in the mirrors (and the oncoming half if you will cross the centre), signal right, then about 3 seconds later accelerate within the speed limit and move gently right, passing on the right with a safe gap. Signal left, continue until the vehicle you passed is fully visible in your rear-view mirror, then move back and cancel the signal.

Can I cross a yellow lane line to change lanes?

No. Where lanes are separated by a yellow line you must not cross it to change lanes. A "no lane change" marking may also apply in one direction only, so check which lane the line restricts.

Do I have to turn into the closest lane?

For a left turn, yes: move as close as possible to the left edge of the road in advance and proceed slowly along that edge. For a right turn, move as close as possible to the centre of the road in advance and pass slowly just inside the centre point of the intersection — on a one-way street, move to the right edge instead.

When can you drive in a tramway?

Only when crossing it to turn left or right, cross the road or make a U-turn, when it is unavoidable in order to prevent danger, or where the "vehicles may use the streetcar track area" sign is posted. Even then you must never obstruct the streetcar, and if one comes up behind you must promptly leave the strip or keep the necessary distance from it.