From the Document: "U.S. residents were asked about instances where they sought help from police (resident-initiated contacts) and when police approached or stopped them (police-initiated contacts). Resident-initiated contacts with police include reporting a crime, disturbance, or suspicious activity; reporting a non-crime emergency such as a medical emergency; reporting a non-emergency such as asking for directions; participating in a block watch or other anti-crime program; or approaching or seeking help from police for another reason. Police-initiated contacts include being stopped by police while in a public place or a parked vehicle (i.e., a street stop), being stopped by police while driving a motor vehicle (i.e., a traffic stop), riding as a passenger in a car that was stopped by police, being arrested, or being stopped or approached by police for some other reason. The PPCS [Police-Public Contact Survey] also collected data on contacts resulting from a traffic accident."
NCJ 255730; National Criminal Justice 255730
U.S. Bureau of Justice Statistics: https://www.bjs.gov/