According to the San Diego study, what percentage of the time can the HGN test determine if a subject's BAC is above 0.08?

The correct answer, which is 88%, is significant because it reflects the reliability of the Horizontal Gaze Nystagmus (HGN) test as a field sobriety test in determining levels of impairment due to alcohol. This percentage is derived from the San Diego study, which highlighted that when the test indicates the presence of nystagmus, there's an 88% chance that a subject's Blood Alcohol Concentration (BAC) is at or above the legal limit of 0.08%.

This statistic emphasizes the effectiveness of the HGN test as a tool for law enforcement in the assessment of suspected DUI offenders. It showcases the correlation between the physiological response of involuntary eye movement and alcohol impairment, lending credibility to the use of the HGN test in roadside evaluations. Understanding this percentage is crucial for anyone involved in DUI enforcement or training, as it underscores the importance of HGN in making informed decisions about sobriety assessments.