The International Cessna^® 170 Association

When cleared for a "Visual Approach", the pilot is responsible for spacing and flight path to avoid wake turbulence.... and death.
And don't allow a previous clearance to "maintian best forward speed" or a specific airspeed to lull you into hitting wake at high speed.
http://www.aopa.org/asf/epilot_acc/chi06fa154.html

Good advice George,

HOWEVER........... don't ever let MOTHER FAA...........fly YOUR airplane. I grew up in the old world of no radios and
then later when flying for UNCLE knew I could "talk back" to a controller or whatever if I didn't like what was happening. I think now in the "modern world of aviation" many defer to letting MOTHER ??? shake the stick if "you" have control??

Buck

Besides proper spacing, the best way to avoid wake turbulence is to fly above the flight path of the aircraft you are following...never below it.