Automatic speed bump
The automatic speed bump senses the speed of the car and adjusts accordingly. If the car stays within the speed limit, the automatic speed limit remains at ground level. This allows cars to pass unobstructed, as long as they don’t speed.
If a car speeds, the speed bump automatically rises, forcing the car to slow down.
One of the situations where automatic speed bumps could be useful would be in an intersection. It would encourage cars to slow down and interact with its surrounding, to determine who goes first through the intersection. This would create a safer environment for vulnerable road users. It would also reduce noise and emissions, as there would be less heavy breaking and speeding up.