How long is a subject timed during the one leg stand test?

During the one leg stand test, the subject is timed for 30 seconds. This duration allows law enforcement officers to adequately observe and assess the subject's balance and coordination while standing on one leg. The test evaluates specific indicators of impairment, including swaying, using arms for balance, hopping, or putting the foot down. Timing the test for 30 seconds strikes a balance between providing enough time to observe these behaviors while keeping the test manageable for the subject. In contrast, shorter or longer durations would either not provide sufficient observation time or might lead to fatigue, which could affect performance unrelated to impairment.