A rumble device, such as rumble strips, provide a visual, audible and vibratory effect used to alert drivers and riders to a hazard ahead and to make them aware of their speed.

Why do they put rumble strips in roads?

Centerline Rumble Strips are an effective countermeasure to prevent head-on collisions and opposite-direction sideswipes (often referred to as cross-over or cross-centerline crashes). Centerline Rumble Strips are primarily used to warn drivers whose vehicles are crossing centerlines of two-lane, two-way roads.

What are yellow painted rumble strips for?

Raised profile line markings or rumble strips are used on the edge of the road or the centre line of the road to let drivers know that they are leaving the lane. They warn drivers in a safe way that there's a risk of either leaving the road or crossing into opposing traffic.