Gaimen50-question practice tests in the real exam formatWhat does 車間距離 (shakan kyori) mean? Following distance
Updated: 2026-10
車間距離 (しゃかんきょり, shakan kyori) means following distance, the gap to the vehicle ahead. Article 26 of the Road Traffic Act (道路交通法) requires a gap large enough to avoid hitting the vehicle ahead even if it stops suddenly. The Rules of the Road (教則) say that on a dry road with new tires you need about 100 m at 100 km/h, and about twice that on a wet road with worn tires.
Legal duty: not "so many meters" but "enough to avoid a collision"
Article 26: "When following directly behind another vehicle travelling the same course, keep the distance necessary to avoid colliding with it even if it stops suddenly." The law sets no fixed number.
The necessary gap depends on your own stopping distance (reaction plus braking distance). The Rules ask you to consider weather, road surface, tires and load, and keep a gap that prevents a rear-end collision.
Spelling and reading: 車間距離 (しゃかんきょり / shakan kyori).
Guide figures from the Rules
Here are the figures in the Rules and the rules of thumb used in test questions.
| Situation | Guide | Source |
|---|---|---|
| Expressway, dry road, new tires, 100 km/h | About 100 m | Rules, Chapter 7 |
| Same, 80 km/h | About 80 m | Rules, Chapter 7 |
| Wet road, worn tires | About twice the above may be needed | Rules, Chapters 7 and 5 (stopping distance can about double) |
| Rainy days (general) | About twice a sunny day | Rule of thumb based on the Rules |
| Snowy or icy roads | About three times a sunny day (even longer) | The Rules say only "sufficient"; no multiplier is given |
When to leave a bigger gap
The Rules call for particular care with following distance in these cases.
- Downhill: the car picks up speed and stopping distance grows
- Rain, snow, ice: braking distance grows
- When tired: reaction distance grows
- Large and medium-sized vehicles: the high driving position makes the gap look longer than it is, so it tends to shrink
- Do not cut in front of cars with beginner or senior driver marks so that they cannot keep the necessary distance (Article 71)
Test traps
Example 1: "In rain, visibility is worse and braking distance is longer, so keep about twice the following distance of a sunny day" → True.
Example 2: "On snowy or icy roads, keep about three times the following distance of a sunny day" → True. Keep it apart from the 2x for rain.
Example 3: Speed questions often pair this with "braking distance is proportional to the square of speed" (double speed, about four times the distance). Speed up, and the gap must grow even more.
Learn the figures in your language
Since October 2025 the knowledge test has 50 True/False questions in 30 minutes; you need 45 correct. Following distance questions use "2x, 3x" and "100 m at 100 km/h". menkyopass lets you practice with English explanations (the first mock test and three topics are free).
Practice questions using this term
FAQ
Q. Does the law set a following distance in meters?
A. No. Article 26 requires a gap large enough to avoid a collision if the vehicle ahead stops suddenly. "About 100 m at 100 km/h" is a guide from the Rules.
Q. Is the guide different for rain and snow?
A. Rain: about twice a sunny day. Snowy or icy roads: longer still, about three times.
Q. Why do large vehicles tend to follow too closely?
A. The high driving position makes the gap look longer than it really is (Rules of the Road).