Gaimen50-question practice tests in the real exam formatWhat does 停止距離 (teishi kyori) mean? Stopping distance
Updated: 2026-10
停止距離 (ていしきょり, teishi kyori) means stopping distance: the distance a car travels from the moment the driver senses danger until it stops. It is the sum of the free running (reaction) distance (空走距離) and the braking distance (制動距離), as explained in the National Police Agency's Rules of the Road (教則). Classic traps: "from when the brakes start working until the car stops = stopping distance" (that is braking distance) and "double the speed, double the braking distance" (it is about four times).
Definition: how the three distances fit together
The term is not in the Road Traffic Act itself but in the Rules of the Road, which the test is based on. According to the Rules, stopping requires the distance travelled from sensing danger and pressing the brake until the brakes actually start working (reaction distance), plus the distance from when the brakes start working until the car stops (braking distance).
Spelling and reading: 停止距離 (ていしきょり / teishi kyori), 空走距離 (くうそうきょり / kūsō kyori), 制動距離 (せいどうきょり / seidō kyori).
| Term | Span | Main causes of a longer distance |
|---|---|---|
| Reaction distance (空走距離) | Sensing danger → brakes start working | Driver fatigue (slower judgment), higher speed |
| Braking distance (制動距離) | Brakes start working → car stops | Wet road, worn tires, heavy load, downhill, higher speed |
| Stopping distance (停止距離) | The two combined | All of the above |
Speed and braking distance: proportional to the square
The Rules explain that braking distance, centrifugal force and impact force all grow with the square of speed. Double the speed and braking distance becomes about four times longer, not twice; triple it and it is about nine times.
Reaction distance is covered at constant speed during the reaction time, so it grows in proportion to speed. A small increase in speed means a much longer stopping distance.
Road surface, tires and the driver
According to the Rules, on a wet road with worn tires the stopping distance can be about twice as long as on a dry road with good tires.
The test asks which distance grows. Road surface, tire condition and load affect the braking distance. Reaction distance depends on the driver's reaction time, so fatigue or drinking lengthens it, while the road surface does not.
Test traps
Example 1: "Stopping distance is the distance from when the brakes start working until the car stops" → False. That is braking distance.
Example 2: "If speed doubles, braking distance roughly doubles" → False. About four times.
Example 3: "On a wet road with worn tires, both reaction and braking distance become more than twice as long" → False. Road and tires affect braking distance only.
Tell the three distances apart in your language
Since October 2025 the knowledge test has 50 True/False questions in 30 minutes; you need 45 correct. Swapping "reaction / braking / stopping" flips the answer. menkyopass lets you practice with English explanations (the first mock test and three topics are free).
Practice questions using this term
FAQ
Q. What is the difference between stopping distance and braking distance?
A. Braking distance runs from when the brakes start working until the car stops. Stopping distance is the total, including the reaction distance from sensing danger until the brakes work.
Q. Which distance gets longer when I am tired?
A. Reaction distance, because recognizing danger and deciding takes longer. As a result, stopping distance grows too.
Q. What happens to braking distance at three times the speed?
A. Braking distance is proportional to the square of speed, so it becomes about nine times longer.