Racial Data Collection at Traffic Stops
"As of March 2001, 16 of the 49 State police agencies with patrol duties required officers to collect the race or ethnicity of all drivers involved in a traffic stop (table 1). Thirty-seven State agencies collected the race or ethnicity of motorists when an arrest was made, and 22 agencies did so following a vehicle or occupant search. Ten State police agencies — Arizona, Arkansas, Idaho, Illinois, Minnesota, Montana, New Mexico, North Dakota, Oklahoma, and Utah — did not require their State troopers to collect race or ethnicity data."
Bureau of Justice Statistics, "Traffic Stop Data Collection Policies for State Police, 2001" (Washington, DC: US Dept. of Justice, December 2001), NCJ 191158 , p. 2.