Weight limitJapan
An introduction to the traffic rules and road signs of Japan. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.
For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.
36. Weight limit
A weight limit prohibits vehicles or vehicle combinations whose mass exceeds the value shown from entering or passing a road section, bridge, tunnel or other structure. Depending on local law, the restriction may concern the vehicle’s actual loaded mass, maximum authorised mass or load on an individual axle.
Drivers must know which type of mass the sign refers to and must include the vehicle, passengers, cargo and any trailer where required. A vehicle that exceeds the limit must use another suitable route.
Wikimedia.org • LERK • CC BY-SA
What should you do if your vehicle exceeds a bridge weight limit in Japan?
Do not drive onto the bridge. Follow the signed alternative route and check the vehicle’s gross and axle loads as applicable. A general heavy-vehicle permit does not automatically authorise crossing every restricted bridge.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
🔗 npa.go.jp • NPA — Traffic Lights and Road Signs, official English definitions
🔗 npa.go.jp • NPA — traffic instruction handbook, sign groups and road use; read with current Act

Traffic rules
Japan