Abstract: An automatic speed sensitive speed bump having a base plate, a front plate hingedly connected to the base plate, and a spring that biases the front plate toward a raised position. A speed-sensitive lock mechanism for locking the front plate in the raised position when impacted by a vehicle tire traveling at a speed at or above a predetermined speed. However, when the vehicle is traveling below the predetermined speed, the front plate is not locked in the raised position and collapses to a horizontal position such that the vehicle does not experience a bump.

Abstract: An automatic speed sensitive speed bump having a base plate, a front plate hingedly connected to the base plate, and a spring that biases the front plate toward a raised position. A speed-sensitive lock mechanism for locking the front plate in the raised position when impacted by a vehicle tire traveling at a speed at or above a predetermined speed. However, when the vehicle is traveling below the predetermined speed, the front plate is not locked in the raised position and collapses to a horizontal position such that the vehicle does not experience a bump.

Abstract: An automatic speed sensitive speed bump having a base plate, a front plate hingedly connected to the base plate, and a torsion spring that biases the front plate upwardly. A rear plate is hingedly connected at its upper end to the front plate. The lower end of the rear plate is beveled and rests on a friction plate, which is hingedly connected at one end to the base plate and is biased upwardly at its other end by a friction plate spring. A strike plate having a reverse beveled end is connected to the base plate. When a vehicle exceeds a predetermined speed, the force of the tires on the front plate causes the rear plate to be driven downwardly rapidly enough and with enough force to depress the friction plate downwardly against the friction plate spring as the lower beveled end of the rear plate is received in the reverse beveled end of the strike plate, which prevents any further rearward movement of the rear plate and therefore locks the speed bump in place.