If you're talking about "rumble strips" which are used to make noise as the car approaches a stop sign, or when it wanders out of its lane on a highway, you have to really loosen up your grip and use your legs as a shock absorber - and ride it out without panicking. It can be treacherous if you're not paying attention.

If you're talking about the large hump-like speed bumps that are put in quiet neighborhoods, parking lots, etc. just slow down and let them function as intended.