How many clues does a subject need to produce in the HGN test to indicate impairment?

How many clues does a subject need to produce in the HGN test to indicate impairment?

• A. 1
• B. 2
• C. 3
• D. 4

Answer: (C)

In the Horizontal Gaze Nystagmus (HGN) test, a subject typically needs to display a minimum of three clues to indicate impairment. The HGN test is a common field sobriety test used by law enforcement to assess whether a driver may be under the influence of alcohol or drugs. The test evaluates the way the eyes track a moving object, with specific focuses on the presence of nystagmus, or involuntary eye movement. The clues that an officer looks for during the HGN test include: 1. The inability of the subject's eyes to track smoothly as the officer moves a stimulus (such as a pen) horizontally. 2. Distinct Nystagmus at maximum deviation, where the eyes show visible signs of nystagmus when looking as far to the side as possible. 3. Onset of Nystagmus prior to a 45-degree angle of the eye from the center. To conclude that a subject is impaired, the presence of three or more of these clues is needed. This benchmark is based on research and guidelines from organizations such as the National Highway Traffic Safety Administration (NHTSA), which support the reliability of the HGN test in indicating impairment due to alcohol or drugs.

In the Horizontal Gaze Nystagmus (HGN) test, a subject typically needs to display a minimum of three clues to indicate impairment. The HGN test is a common field sobriety test used by law enforcement to assess whether a driver may be under the influence of alcohol or drugs. The test evaluates the way the eyes track a moving object, with specific focuses on the presence of nystagmus, or involuntary eye movement.

The clues that an officer looks for during the HGN test include:

1. The inability of the subject's eyes to track smoothly as the officer moves a stimulus (such as a pen) horizontally.

2. Distinct Nystagmus at maximum deviation, where the eyes show visible signs of nystagmus when looking as far to the side as possible.

3. Onset of Nystagmus prior to a 45-degree angle of the eye from the center.

To conclude that a subject is impaired, the presence of three or more of these clues is needed. This benchmark is based on research and guidelines from organizations such as the National Highway Traffic Safety Administration (NHTSA), which support the reliability of the HGN test in indicating impairment due to alcohol or drugs.