What does 徐行 (jokō) mean? Japan's "slow down" rule

Legal definition: not a number, but "able to stop at once"

Article 2(1)(xx) of the Road Traffic Act defines jokō as "proceeding at a speed at which the vehicle can stop immediately". The National Police Agency's Rules of the Road (交通の方法に関する教則), the source for the test, says the same.

Driving schools sometimes say "about 10 km/h or less", but neither the law nor the Rules contain any figure. So "jokō means driving at 10 km/h or less" is False. How slow is slow enough depends on the road surface and visibility.

Spelling and reading: 徐行 (じょこう / jokō). The sign is a red inverted triangle with 「徐行」 written on it.

The five places where you must slow down (Article 42)

Test questions swap "steep downhill" for "steep uphill", or a blind intersection for one with a clear view.

Situations that require jokō (main ones)

Besides places, these situations require slowing down. The test point: the law asks only for jokō here, not a full stop.

• Turning left or right (Article 34). On a one-way road, move to the right edge in advance and turn right inside the center of the intersection at jokō
• Entering a priority road or a clearly wider road (Article 36(3))
• Passing pedestrians when you cannot leave a safe gap (Article 18(2))
• Passing a safety zone (安全地帯) with pedestrians on it (Article 71)
• Passing a stopped school or kindergarten bus while children get on or off (Article 71)
• Passing a stopped streetcar: only if there is a safety zone, or nobody is getting on or off and you can keep 1.5 meters or more (Article 31)

Test trap: where slowing down is not enough

When a statement says "you may proceed after slowing down and checking for safety", ask whether a full stop (一時停止) is required instead.

Practice "jokō or full stop" in your language

Since October 2025 the knowledge test has 50 True/False questions in 30 minutes, and you need 45 correct. Jokō questions are easy points once you know the definition and the five places. menkyopass lets you practice with English explanations (the first mock test and three topics are free).

Practice questions using this term

• At an intersection with this sign, you may drive through as long as you slow down and check that it is safe.
• Slowing down (slow driving) means driving at a speed of 10 km/h or less.
• At a flashing red light, vehicles may enter the intersection at a slow speed without stopping.
• When turning right on a one-way road, you must move as close as possible to the right edge of the road in advance, and drive slowly through the inside of the intersection's center.
• When a pedestrian is about to cross at a pedestrian crossing, it is enough to slow down and let the pedestrian go.
• When a stopped streetcar has no one getting on or off, there is no safety zone, and you can keep a gap of at least 1.5 meters from the streetcar, you may proceed at a slow speed.
• A steep uphill slope is a place where you must slow down (to a speed at which the vehicle can stop immediately).
• Near a bend in the road, you must drive slowly enough to stop immediately, even when you have a clear view.

FAQ

Related guides

• Japan Speed Limits: 60 km/h, 30 km/h Residential Roads, Mopeds 30
• Right of Way in Japan: Intersections, Pedestrians, Emergencies
• What does 一時停止 (ichiji teishi) mean? Full stops in Japan
• 徐行 vs 一時停止: Slow Down vs Full Stop in Japan's Test

Sources (in Japanese)

• e-Gov法令検索「道路交通法」（第2条第1項第20号・第18条・第31条・第34条・第36条・第42条・第71条）
• 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）第5章第3節・第4節