Safe Speed & Stopping Distance

"Obeying the speed limit" isn't always enough for safety.
We explain the basics of safe driving, including the mechanics of stopping a car and places where you must slow down.

3 Concepts of Speed

There are 3 criteria for judging "how fast to drive".

① Regulated Speed (Kisei Sokudo)
The maximum speed designated by signs or markings.
e.g., If there is a "40" sign, it's 40km/h.
② Legal Speed (Hotei Sokudo)
The maximum speed determined by law on roads without signs.
Cars: 60km/h / Mopeds: 30km/h

⚠️ Important Rule:
You must always obey the lower of the "Regulated Speed" and "Legal Speed".

③ Safe Speed
Speed considering weather and road conditions.
On rainy or snowy days, you need to slow down sufficiently below the maximum speed.

Distance to Stop (Stopping Distance)

A car doesn't stop immediately when you brake. There are two stages until a car stops.

Stopping Distance
||
Reaction Distance + Braking Distance
  • ● Reaction Distance (Kuso Kyori)
    Distance traveled from perceiving danger until the brakes start working. (Reaction time)
  • ● Braking Distance (Seido Kyori)
    Distance traveled from when brakes start working until the car stops completely.

📝 Rule of Thumb
Stopping distance on general roads (30-60km/h) is roughly:
"Speed minus 15 = Stopping Distance (m)".
e.g., At 60km/h, 60 - 15 = approx. 45m is needed to stop!

5 Places to Slow Down (Joko)

"Slow Down" (Joko) means proceeding at a speed where you can stop immediately (generally 10km/h or less). You must slow down in these places:

  • Places with "Slow Down" signs
  • Intersections with poor visibility to left/right
    (*Except if there are traffic lights or priority roads)
  • Near road corners
  • Near the top of uphill slopes
  • Steep downhill slopes

Prevent accidents with a "Safe Speed"
suited to the situation!

Training for Success!