I’m confused by speed bumps. If a neighborhood wants you to drive 15 or 20 miles an hour down their street, why put in speed bumps that can only be negotiated at 5 miles per hour? That guarantees braking, bouncing, and accelerating for every bump! Why not put in speed bumps that are comfortable at 15 miles per hour, but uncomfortable above? That would accomplish what they’re after; reduced speed, and also reduce noise, and pollution from acceleration.