How is impairment typically determined during the SFST battery?

Impairment during the Standardized Field Sobriety Test (SFST) battery is indeed determined by the number of clues or indicators of intoxication observed during each test. The SFST consists of a series of standardized tests designed to allow law enforcement officers to assess a suspect's physical and cognitive abilities. These tests are scientifically validated and provide a structured approach to identifying impairment due to alcohol or drugs.

During the tests, specific cues are looked for, such as swaying, difficulty balancing, or improper use of instructions. Each of these cues provides tangible evidence of impairment that can be documented and used in legal proceedings. The systematic observation of these indicators allows an officer to make an informed determination regarding the level of impairment, which is necessary for enforcing DUI laws.

Determining impairment based solely on a subject's demeanor lacks the objectivity and scientific foundation that the SFST provides. Similarly, relying on the duration of each test does not accurately reflect impairment, as it is the observed signs and not the time taken that matters. Additionally, personal biases of the officer should not play a role in the assessment, as all evaluations must be based on standardized, observable factors to ensure fairness and accuracy in the determination of impairment.