What must a subject do during the walking stage of the Walk and Turn test?

During the walking stage of the Walk and Turn test, the subject must count out loud. This requirement serves multiple purposes: it not only helps keep the subject focused on the task at hand, but it also provides the officer with observable behavioral cues that can be indicative of the subject's impairment level. Counting aloud can help assess whether the individual can balance and concentrate simultaneously, which is a critical aspect of the test.

In this context, counting silently or performing other tasks, such as reciting the alphabet, would not produce the same level of auditory feedback for the officer or engage the necessary cognitive functions involved in the assessment of sobriety. Additionally, walking in a straight line is an important part of the test, but the specific requirement to count out loud distinguishes this particular component of the assessment process.