What is a primary reason for officers to use police units in traffic direction?

The primary reason for officers to use police units in traffic direction is to serve as a physical barrier. This function helps in creating a safe environment for both the officers directing traffic and the motorists, particularly in situations where traffic flow needs to be managed effectively. The presence of police vehicles can deter reckless driving behaviors and guide vehicles safely through congested or hazardous areas.

While visibility is also important, enhancing visibility is typically a secondary benefit that comes from the act of using police units. Pedestrian movement restrictions are not a primary purpose of police units in traffic direction, as officers typically aim to ensure the safety of both drivers and pedestrians. Controlling vehicle emissions is not a relevant function of police units in this context; their primary role in traffic direction revolves around safety and efficient traffic management.