Which test has the lowest accuracy rate among the three tested in isolation?

The One-Leg Stand (OLS) test is often considered to have the lowest accuracy rate when assessed in isolation compared to the other two standardized field sobriety tests, the Horizontal Gaze Nystagmus (HGN) and Walk-and-Turn (WAT).

The OLS requires the subject to stand on one leg for approximately 30 seconds while counting aloud. This test is influenced by several factors, such as the subject's physical condition, balance, and ability to follow instructions, which can lead to variability in results. If a person has pre-existing balance issues or is nervous or distracted, their ability to successfully complete this task may be compromised, leading to a higher likelihood of false positives for impairment.

On the other hand, both the HGN and the WAT provide more structured responses that correlate better with impairment levels. HGN focuses on eye movements, which can provide a clear indication of impairment based on physiological responses. The WAT is a multi-step task that not only assesses balance but also requires the subject to follow specific cognitive instructions, which can effectively separate sober individuals from those who are impaired.

Therefore, the OLS, while useful, is less reliable in isolation when compared to the other tests that consistently show higher accuracy rates in