DUI Traffic Stops Practice Test: Prep & Practice Exam Study Guide

During the Horizontal Gaze Nystagmus (HGN) test, the object should be positioned 12-15 inches from the driver's nose to ensure accurate results. This distance allows for optimal visibility of the eye's movements while testing for signs of nystagmus, which can indicate impairment due to alcohol or drugs. At this range, the officer can effectively monitor the subject's eye tracking, ensuring that both the left and right eyes are tested similarly for consistency in observing the eye's reaction to the object being moved horizontally. By adhering to this distance, the officer can maintain the integrity of the test and obtain reliable indicators of impairment.