Which of the following is NOT one of the three standardized tests for OUI?

The breath test is not considered one of the three standardized field sobriety tests (SFSTs) for Operating Under the Influence (OUI). The three standardized tests recognized for evaluating a driver's impairment in the context of OUI enforcement are horizontal gaze nystagmus, walk and turn, and one leg stand.

Horizontal gaze nystagmus assesses the ability of the eyes to track a moving object and looks for involuntary eye movements that indicate impairment. The walk and turn requires the individual to walk a straight line heel-to-toe and then return, testing balance and coordination. The one leg stand involves balancing on one leg for a set amount of time, which also evaluates balance and physical control.

In contrast, the breath test is a chemical test that measures the blood alcohol concentration (BAC) of an individual by analyzing breath samples. While it is a critical component of OUI enforcement and serves as an evidence-gathering tool, it is not classified as a field sobriety test and therefore is not included in the trio of standardized tests that are typically administered in the field for assessing impaired driving.