On a road with no posted speed limit sign, there is no speed limit at all and you may drive at any speed.

Explanation

Even without a sign, the statutory speed limit still applies. You must not exceed it, so the road is never speed-unlimited.

Guides that explain this

• Stopping Distance in Japan: Reaction Distance + Braking Distance
• Overtaking and Lane Rules in Japan: Where It Is Banned, and How

Related terms

• Statutory speed limit (hōtei sokudo)

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