|If the train track gets bumpier in effect with increasing speed, why is it that your car bumps less when you go over a speed bump fast instead of slow?
Actually, if you drive fast over a real speed bump, it's not good for your wheels and suspension. The springs in your car do protect the car from some of the effects of the bump, but not all of them. However, imagine driving over a speed bump on a traditional bicycle—one that has no spring suspension. The faster you drive over that bump, the more it will throw you into the air.