ZoneJapan
4. Zone
A traffic zone is an area in which a traffic rule applies throughout all included roads or road sections. The rule normally begins at a zone-entry sign and remains applicable until the corresponding end-of-zone sign is passed.
Zones may regulate speed, parking, access, vehicle categories, emissions or other traffic behaviour. The signs used, the roads covered and the effect of intersections or local exceptions depend on local traffic law.
Wikimedia.org • 円周率3パーセント • CC BY-SA
How do people refer to traffic zones in Japan?
The Japanese name ゾーン30 means Zone 30. It establishes an area with a 30 km/h maximum. ゾーン30プラス, Zone 30 Plus, combines that area restriction with physical traffic-calming measures.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
🔗 mlit.go.jp • MLIT/NPA — Zone 30 Plus: area restriction and physical traffic calming
Where does a zone rule apply in Japan?
The 30 km/h restriction covers the designated area, rather than only the point bearing the entrance sign. Observe its boundary signs and other restrictions on the roads inside it.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
🔗 mlit.go.jp • MLIT/NPA — Zone 30 Plus: area restriction and physical traffic calming
Does Japan’s Zone 30 Plus allow a different maximum speed from Zone 30?
No. The maximum remains 30 km/h. The Plus arrangement adds measures such as humps to reinforce the restriction and improve safety; it does not give permission to drive faster between them.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
🔗 mlit.go.jp • MLIT/NPA — Zone 30 Plus: area restriction and physical traffic calming
Is every Japanese road limited to 30 km/h necessarily inside a Zone 30?
No. A separately signed road or the statutory limit for qualifying ordinary roads can also be 30 km/h. Zone 30 identifies an area restriction; one road’s numerical limit alone does not establish its boundary.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
🔗 mlit.go.jp • MLIT/NPA — Zone 30 Plus: area restriction and physical traffic calming

Traffic rules
Japan