PotholeJapan

Learn traffic rules with clear explanations and visual examples in our illustrated book, designed to make studying simple and engaging.


74. Pothole

A pothole is a hole or depression in the road surface caused by wear, weather, water, repeated traffic loads or deterioration of the pavement. Potholes can vary greatly in size and depth and may develop gradually or become worse after freezing, heavy rain or repeated vehicle traffic.

Potholes can affect steering, braking and vehicle stability and may damage tyres, wheels or suspension components. Drivers and riders should observe the road ahead, adapt their speed and avoid sudden or dangerous manoeuvres when encountering damaged road surfaces.

Pothole
Car caught in a large pothole.
Wikimedia.org • State Farm • CC BY
What is a pothole?

A pothole is a hole or depression that develops in a road surface when the pavement becomes damaged or deteriorates.

How do potholes form?

Potholes can develop through a combination of water, temperature changes, traffic loads and deterioration of the road material. Cracks can gradually expand until pieces of the surface break away.

Why are potholes dangerous?

A pothole can cause a vehicle to change direction suddenly, lose stability or suffer tyre, wheel or suspension damage. Deep potholes can present a particularly serious hazard at higher speeds.

What should you do when you see a pothole?

Reduce speed when necessary, maintain control of the vehicle and avoid abrupt steering or braking. Only move around the pothole when this can be done safely without endangering other road users.

Should you brake while driving through a pothole?

If possible, reduce your speed before reaching the pothole. Sudden heavy braking or steering while passing over a damaged surface can make the vehicle less stable.

Are potholes particularly dangerous for motorcycles?

Yes. A pothole can disturb the steering or balance of a motorcycle and may cause the rider to lose control.

Are potholes dangerous for cyclists?

Yes. Bicycle wheels can be strongly affected by deep holes or sharp edges, particularly when the cyclist has little time or space to avoid the hazard.

Can a pothole damage a car?

Yes. Severe impacts can damage tyres, wheel rims, suspension components, steering parts or wheel alignment.

Should you swerve suddenly to avoid a pothole?

No. A sudden evasive movement may create a greater danger by bringing the vehicle into conflict with cyclists, pedestrians, oncoming traffic or vehicles in another lane.

Can a warning sign indicate potholes ahead?

Yes. Depending on the country's traffic-sign system, an uneven-road or general-danger warning sign may be used where poor road conditions create a significant hazard.

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