The Bureau of Justice Statistics released a study that says while Whites, Blacks and Latinos get pulled over in traffic in equal measures, Blacks and Latinos are more likely to get arrested. The study that covered police interactions with civilians in 2005 as well as Census interviews, does not explain why these disparities occur. Presumably the government can figure it out in another couple of years. Meanwhile, a reporter for Associated Press has a theory:

Traffic stops have become a politically volatile issue...Blacks in particular have complained of being pulled over for simply “driving while black.”

Could this be true? On Los Angeles WB affiliate KTLA, we heard a reporter say that many factors weigh in. Like that people of color are more likely to have drugs on them. Oh.

Black, Latino drivers fare worse in traffic stops [MSNBC]
Image [City of Tacoma Park]