Most agencies (27) relied on their officers' observation of the driver's race or ethnicity as the method of determining the race or ethnicity of the motorist. Officer observation was the exclusive method in 15 State agencies.  Twelve agencies also used information on motorist race
or ethnicity from the State Bureau of Motor Vehicles or equivalent agency. This method was used exclusively by two agencies.

Eleven agencies also used information provided orally by the motorist. None of the State agencies used this method alone.

Nine of the State agencies used all three sources (officer observation, motorist self identification, and Bureau of Motor Vehicle data) to determine the driver's race or ethnicity.

Among the 29 State police agencies that collected race or ethnicity information on at least some kinds of traffic-related stops, almost all (26) stored these data electronically. Ten stored the data using only electronic means, and 16 used both electronic and paper-based
storage. Three agencies used paper storage only.

Seventeen agencies that collected race or ethnicity data linked their traffic stop data to other law enforcement information systems such as dispatch information, citations, officer logs, or bureau of motor vehicle records.

Twenty-two of the 29 State police agencies that collected race or ethnicity data under at least some traffic stop circumstances, made their data available to the public. Nine agencies published reports based on the data.