What is the purpose of the SFST in OUI investigations?

The purpose of the Standardized Field Sobriety Tests (SFST) in Operating Under the Influence (OUI) investigations is primarily to assess impairment. These tests are designed to evaluate a driver's physical and mental abilities, helping law enforcement determine whether a person is impaired by alcohol or drugs.

During an OUI investigation, officers will use SFSTs, which typically include tasks such as the Horizontal Gaze Nystagmus test, Walk-and-Turn test, and One-Leg Stand test. Each of these tests evaluates different aspects of a driver's coordination, balance, and ability to follow instructions—key indicators of impairment. Officers are trained to observe and interpret the results of these tests, which can provide substantial evidence of a driver's impairment level at the time of the traffic stop.

While confirming an arrest, facilitating further testing, or providing statements for court are all relevant aspects of the overall OUI process, they do not capture the primary function of SFSTs, which is to provide a systematic method for assessing an individual's level of impairment during a traffic stop.