Gravel Road Speed Bumps

A speed bump (ralentisseur) is a convex road feature—like a small hump—designed to force drivers to slow down, ensuring effective braking when pedestrians may enter the road. While common on paved urban roads, they are also used on gravel or dirt tracks where pedestrian safety is a concern.

Gravel road issues

Gravel roads are public, unpaved roads. The UK Highway Code equivalent limits speeds to 30 mph in urban areas and up to national speed limits outside. On loose surfaces, fast driving kicks up dust, gravel and sand, causing nuisance and hazards for local residents. Braking distances increase on such surfaces, raising accident risks. Municipal authorities should therefore consider speed cushions on gravel roads where excessive speed is reported.

Why install speed bumps on gravel roads?

According to road regulations, speed calming measures are allowed on local roads and access tracks. Bumps must be no more than 10 cm high to avoid vehicle damage or suspension issues. Residents often report significant speed reduction post-installation. These measures are usually implemented by local councils, often following a petition signed by residents.

Characteristics of speed bumps

• Made from rubber or concrete, with high wear resistance.

• Non-slip surface for safety.

• Fitted with reflective elements, effective at night, in bright colours like yellow or red.

• Permanently anchored to the road surface.

• Suitable for residential zones, school areas, car parks, shopping centres and service stations.

• Modular design: central and side units, various shapes:

  • Island type (slows cars but allows bus wheels to pass)

  • Longitudinal strip type, ideal for full-width gravel roads, limiting speed to 20–30 mph

• Designed to provide a smooth ride at the intended speed, composed of several middle, side units and fasteners (permanent or temporary).

Regulatory compliance

Proper signage is mandatory:

• Warning sign A‑11a,

• Speed limit sign B‑33,

• Distance plate T‑1.