Japanese Road Signs: Common Mistakes in the Conversion Test

Four types of main signs, plus auxiliary signs

Japanese signs are divided into main signs (本標識) and auxiliary signs (補助標識). There are four types of main signs: regulatory (規制標識), instruction (指示標識), warning (警戒標識) and guide signs (案内標識). An auxiliary sign is attached below a main sign and limits it by time, day or vehicle type.

Similar pictures can belong to different types. The blue sign with a white pedestrian (横断歩道) is an instruction sign marking the crossing itself, while the yellow diamond with children (school or kindergarten ahead) is a warning sign.

Signs with similar names but different meanings

These pairs are tested most often. A sign prohibits only the act it shows and nothing more (for example, No U-turn prohibits only U-turns, not backing up).

Signs and markings with numbers

Questions usually ask what a number means rather than the number itself. Maximum and minimum speed signs differ only by an underline, but their meanings are opposite.

STOP versus slow down

At an intersection with a STOP sign (止まれ / 一時停止), you must come to a complete stop just before the stop line, or just before the intersection if there is no line (Road Traffic Act, Article 43). Slowing down and checking is a violation. After stopping, you still must not obstruct traffic on the crossing road.

“Slow down” (徐行) is defined as driving at a speed at which the vehicle can stop immediately. The law gives no km/h figure, so a statement like “slow down means 10 km/h or less” is False.

When passing a safety zone (安全地帯) with pedestrians in it, your duty is to slow down; a full stop is not required. Driving into a safety zone is always prohibited, whether or not people are there.

In a section with a horn zone sign (警笛区間), you must sound the horn only at blind intersections, blind curves and blind hilltops. You do not keep honking; elsewhere the horn may be used only when unavoidable to prevent danger.

Lanes and road markings

A bus-only lane (専用通行帯) may still be used by small special vehicles, mopeds and light vehicles. Ordinary cars may not use it, except when moving to the side or center of the road to turn, or when unavoidable because of road work.

A bus priority lane (優先通行帯) may be used by ordinary cars, but you must leave it promptly when a route bus approaches. If traffic is so heavy that you might not be able to leave, do not enter it in the first place.

The yellow-framed “no stopping zone” marking (停止禁止部分) prohibits stopping inside it, but you may drive through. The marking that prohibits entering at all is the “keep out zone” (立入り禁止部分).

A white plate with a blue left arrow (左折可) means you may turn left even on a red or yellow light, while watching surrounding traffic. It is different from the blue One Way sign (一方通行) with a white arrow.

Common trap patterns

Almost every False statement in this topic follows one of these patterns. Identify the pattern first and you will answer faster.

• Wrong target: side-by-side riding is for 2 ordinary bicycles, not motorcycles
• Over-extended scope: No U-turn also banning backing up, or honking continuously in a horn zone — both False
• Stopping vs parking: loading within 5 minutes is allowed under a No Parking sign
• Ignoring the auxiliary sign: “Except mopeds” means mopeds may pass; outside “8-20” there is no restriction
• Strength of the duty: STOP sign = complete stop; pedestrians in a safety zone = slow down
• Definitions of numbers: “slow down” has no figure; an underlined number is a minimum speed

Practice sign questions in your language

Since October 2025 the knowledge test (知識確認) is 50 written True/False questions and you need 45 correct; sign questions are also written in text. menkyopass's conversion drill lets you practice sign questions with English explanations (first mock exam and 3 topics free; full access ¥1,500 one-time).

Practice questions on this topic

• On a road with this sign, up to three motorcycles may ride side by side.
• At an intersection with this sign, you may drive through as long as you slow down and check that it is safe.
• Where this sign is posted and there is no stop line, you must stop just before the intersection.
• Where this sign is posted, not only parking but also stopping is prohibited.
• Even where this sign is posted, you may stop to let people get on or off.
• Even where this sign is posted, stopping for up to 5 minutes to load or unload goods is not a violation.
• Within the zone covered by this sign, you must drive with your horn sounding at all times.
• Slowing down (slow driving) means driving at a speed of 10 km/h or less.
• On a road with this sign, vehicles cannot enter from either direction.
• On a road with this sign, no motor vehicles, motorized bicycles (mopeds), or light vehicles (bicycles, etc.) may pass.
• On a road with this sign, vehicles cannot pass but pedestrians can.
• Where this sign is posted, you may neither make a U-turn nor reverse.
• Where this sign is posted, you may overtake as long as you do not cross into the right half of the road.
• This sign has the same meaning as the 'Left Turn Permitted' board, which shows a blue left arrow on a white background.
• A sign showing the number 30 with a line under it means you must not drive faster than 30 km/h.
• Even small special motor vehicles, motorized bicycles (mopeds), and light vehicles must not drive in a lane reserved exclusively for route buses (bus-only lane).
• A priority lane for route buses means the same as a bus-only lane, so regular cars must not drive in it.
• The Pedestrian Crossing sign is an instruction sign showing a pedestrian in white on a blue background.
• If a Closed to Vehicles sign has an auxiliary plate reading 'except mopeds,' motorized bicycles (mopeds) still cannot use the road.
• The main road signs come in four types: regulatory signs, instruction signs, warning signs, and guide signs.
• Where the road marking 'No Stopping Zone' framed in yellow is painted, you must not enter that area to drive through it.
• When passing a safety zone with pedestrians in it, you must come to a complete stop.
• Where there is a 'maximum height 3.3 m' sign, vehicles whose height, including the load, exceeds 3.3 meters cannot pass.
• If a No Parking sign has an auxiliary plate reading '8-20,' parking is prohibited only between 8 a.m. and 8 p.m.

FAQ

Related guides

• Japan Traffic Light Rules: Yellow, Flashing, Arrows, Signals
• Japan Parking and Stopping Rules: 5 m, 10 m, 3 m, 1 m
• Overtaking Rules in Japan: No-Overtaking Zones and Passing
• Right of Way in Japan: Intersections, Pedestrians, Emergencies

Sources (in Japanese)

• 警察庁「交通の方法に関する教則」（令和6年11月13日現在・全文PDF）
• e-Gov法令検索「道路交通法」
• e-Gov法令検索「道路交通法施行令」
• 警視庁「令和7年10月1日施行・改正道路交通法施行規則について」