"In both 2002 and 2005, white, black, and Hispanic drivers were stopped by police at similar rates, while blacks and Hispanics were more likely than whites to be searched by police. About 5% of all stopped drivers were searched by police during a traffic stop. Police found evidence of criminal wrong-doing (such as drugs, illegal weapons, or other evidence of a possible crime) in 11.6% of searches in 2005."

Source

Durose, Matthew R., Smith, Erica L., and Langan, Patrick A., PhD, "Contacts Between Police and the Public, 2005," (NCJ215243) (Washington, DC: Bureau of Justice Statistics, April 2007), p. 1.
http://www.bjs.gov/content/pu…