What is the accuracy percentage for the Horizontal Gaze Nystagmus (HGN) test?

The Horizontal Gaze Nystagmus (HGN) test is a field sobriety test used by law enforcement to assess a driver's level of impairment due to alcohol consumption. This test evaluates the involuntary eye movement known as nystagmus, which can be indicative of intoxication.

The accuracy percentage of 88% is derived from studies involving the test's ability to predict blood alcohol concentration (BAC) and identify impairment accurately. This figure highlights the test's reliability, demonstrating that when administered properly, it can accurately identify a significant percentage of impaired drivers. The HGN test is particularly effective because nystagmus becomes more pronounced with increasing levels of alcohol in the bloodstream, making it a valuable tool for officers in the field.

In contrast, the other options present accuracy percentages that are lower than the established 88%. While different studies may report varied outcomes, the consensus among law enforcement training standards recognizes 88% as a reliable benchmark for the HGN test's effectiveness in detecting impairment.