A speed hump (also called a road hump or undulation,[1] and in Ireland called a speed ramp) is a rounded traffic calming device used to reduce vehicle speed and volume on residential streets. Humps are placed across the road to slow traffic and are often installed in a series of several humps in order to prevent cars from speeding before and after the hump. Common speed hump shapes are parabolic, circular, and sinusoidal.[1]