Why are speed humps and speed tables considered effective measures for speed reduction?

Speed humps and speed tables are considered effective measures for speed reduction primarily because they physically alter the driving conditions, compelling drivers to slow down. The design of speed humps and tables creates an obstacle that requires vehicles to reduce their speed to safely navigate over them. This intentional disruption of a vehicle's travel speed directly addresses the issue of speeding, particularly in areas where lower speeds are necessary for safety, such as residential neighborhoods, school zones, or areas with high pedestrian activity.

While improving visibility, providing a smoother ride, and being cost-effective may have their merits in different contexts, these factors do not directly contribute to the primary function of speed humps and tables, which is to enforce a reduction in speed through physical means. The effectiveness of these traffic calming measures lies in their ability to alter driver behavior simply through their physical presence on the roadway.