Patrol and Traffic Operations
Core concepts
Understand the purposes of patrol (prevention, deterrence, apprehension, service), directed versus random patrol, and the elements of a lawful traffic stop. Know the standard for stopping a vehicle (reasonable suspicion of a violation), the scope of the stop, and how it can expand. Know DUI detection: the three phases (vehicle in motion, personal contact, pre-arrest screening), standardized field sobriety tests (horizontal gaze nystagmus, walk-and-turn, one-leg stand), and implied consent concepts. Know crash-scene management: scene safety, blocking, triage, and documentation.
Traps
A common trap is assuming a traffic stop can be extended indefinitely; the stop must remain reasonably related to its purpose, though a K-9 sniff may be permissible if it does not prolong the stop. Another trap conflates a traffic infraction with a criminal offense. Questions often test whether an officer may order occupants out of a vehicle (generally yes) versus search the vehicle (requires probable cause or another exception).
Rule of thumb
For any traffic-stop question, ask: What justified the stop? What justified each additional step? Did any step prolong the stop beyond its mission without independent justification? Each answer must rest on its own facts.
Worked example
An officer stops a car for a burned-out taillight. During the lawful stop, the officer smells alcohol and observes slurred speech. That combination supports reasonable suspicion of impairment and justifies moving to the DUI investigation phase; the original infraction alone would not.