SlopeJapan
14. Slope
A slope is a section of road that rises or descends noticeably. A steep slope can affect vehicle speed, braking distance, traction, visibility and the ability of heavy or low-powered vehicles to maintain a steady speed.
Warning signs may indicate a steep ascent or dangerous descent and may show the gradient as a percentage. Drivers should adjust their speed early, select a suitable gear and remain prepared for slow vehicles, bends and changing road conditions.
Wikimedia.org • Kestrel • CC BY-SA
What does a steep-slope warning mean in Japan?
Japanese warning signs identify steep ascent or descent hazards. Keep a speed suited to the road and read any separate restrictions before entering a narrow or winding slope.
🔗 laws.e-gov.go.jp • Japan Road Traffic Act — Articles 30, 42 and 70
🔗 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
Warning for a steep ascent.
English • Traffic sign 212の3 • Steep ascent: 10%. Select a speed and gear suitable for road conditions.
日本語 • 212の3 • 上り急勾配あり:10%。 この先に勾配10%の急な上り坂があります。道路状況に適した速度とギアを選んでください。
Sources
🔗 Commons.wikimedia.org
🔗 Laws.e-gov.go.jp • 道路標識、区画線及び道路標示に関する命令、別表第一・第二
🔗 Mlit.go.jp • 国土交通省、道路標識一覧
SVG source: Monaneko • Public domain • Original revision 2013-06-19. Wikimedia original unmodified.
Warning for a steep descent.
English • Traffic sign 212の4 • Steep descent: 10%. Use an appropriate gear to avoid excessive speed.
日本語 • 212の4 • 下り急勾配あり:10%。 この先に勾配10%の急な下り坂があります。速度が上がりすぎないよう、適切なギアを使ってください。
Sources
🔗 Commons.wikimedia.org
🔗 Laws.e-gov.go.jp • 道路標識、区画線及び道路標示に関する命令、別表第一・第二
🔗 Mlit.go.jp • 国土交通省、道路標識一覧
SVG source: Monaneko • Public domain • Original revision 2013-06-19. Wikimedia original unmodified.
How should I approach a steep descent in Japan?
Reduce speed before the descent and select a suitable gear to help control the vehicle. Keep enough following distance and avoid building up speed that requires continuous heavy braking. A warning gives no fixed safe descent speed: the gradient, surface, visibility, load and vehicle can require a speed well below the legal maximum.
🔗 laws.e-gov.go.jp • Japan Road Traffic Act — Articles 30, 42 and 70
🔗 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
What should I check when meeting or overtaking on a slope in Japan?
Japan’s Road Traffic Act prohibits overtaking near a hilltop and on a steep downhill slope, subject to the Act’s provisions. Do not treat an apparently empty road beyond the crest as a safe place to pass.
🔗 laws.e-gov.go.jp • Japan Road Traffic Act — Articles 30, 42 and 70
🔗 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