Radar speed signJapan
37. Radar speed sign
A radar speed sign warns drivers that vehicle speeds may be monitored by a fixed camera, mobile radar, lidar or average-speed enforcement system. It reminds drivers to check and respect the applicable speed limit.
The sign does not normally establish the speed limit itself. Drivers must follow the general, posted or variable speed limit applying to the road and must not brake suddenly merely because speed enforcement is indicated.
Wikimedia.org • Worldx • CC BY-SA
What should a driver understand from a radar or speed-camera warning in Japan?
A notice warning of speed monitoring is separate from a regulatory speed-limit sign. Obey the applicable road, vehicle and posted maximum regardless of whether equipment is visible. Do not infer the exact equipment, coverage or a legal duty to provide a warning from a camera pictogram alone.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
Which speed limit applies when a radar warning is displayed in Japan?
Follow the speed-limit sign, applicable speed zone or statutory road and vehicle limit. A camera symbol or enforcement notice must not be mistaken for a sign raising or ending that limit.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text
Should you brake abruptly when you notice a radar sign in Japan?
No. Adjust to the lawful and safe speed smoothly, leaving adequate space behind and ahead. Enforcement information does not authorise sudden unsafe manoeuvres or stopping to inspect the camera.
🔗 laws.e-gov.go.jp • e-Gov — current enforced Road Traffic Act, revision metadata and full text

Traffic rules
Japan