What is standard field sobriety testing designed to assess, and what are the three tests commonly used?

• A. Breathalyzer results determine impairment.
• B. Impairment due to alcohol or drugs; horizontal gaze nystagmus, walk-and-turn, and one-leg stand.
• C. They assess memory function.
• D. They are never used in DUI investigations.

Answer: (B)

Standard field sobriety tests are designed to determine impairment from alcohol or drugs, rather than to measure an exact level of intoxication. The three tests commonly used are horizontal gaze nystagmus, walk-and-turn, and one-leg stand. The horizontal gaze nystagmus test checks for involuntary eye jerking that can appear with intoxication; the walk-and-turn test assesses balance, coordination, and the ability to follow instructions as the person takes steps and turns; the one-leg stand test gauges balance and the ability to maintain posture while counting or focusing, all while divided attention is challenging. These tests help officers decide if there is probable cause to arrest for impaired driving. The other statements don’t fit because the breathalyzer is a chemical BAC test, not a field sobriety test; the tests aren’t about memory function; and they are routinely used in DUI investigations.