A speed hump is a raised portion of the street surface that is slightly longer than an average automobile and spans the width of the street.
A speed bump, usually 12 inches wide and between three and six inches high, forces vehicles to travel as slow as 15 mph on local streets, creating a safer pedestrian environment. Speed bumps are sometimes found in parking lots and toll plazas. However, they are no longer legal on city streets, because their height can cause motorcycles and bicycles to lose control, as well as vehicle damage.
