Field Sobriety Tests: Walk and Turn

 The National Highway and Traffic Safety Administration has designated as standardized only three of the multitude of field sobriety tests used by law enforcement to estimate a suspected DUI driver’s BAC: the horizontal gaze nystagmus test, the one-leg stand test and the walk and turn test.  According to NHTSA studies, the walk and turn test, alternately known as the walk the line test, the nine step test or the nine step walk turn test, when administered properly, is 68 per cent accurate in identifying a BAC higher than 0.10 per cent.  However, this seemingly high rate can be questioned if proper testing protocols are not followed, and other factors may play a role in casting doubt on the test results.

The Test

NHTSA procedures require the testing officer to precisely describe and demonstrate the walk and turn test, but the basic test consists of:

• The subject places one foot in front of the other, heel-to-toe, on a natural line or one created by the officer
• At the officer’s direction, the subject takes nine heel-to-toe steps, turns around by taking a small number of steps and takes nine heel-to-toe steps to return to the starting point
• Arms are to be held to the side and the test should be completed without stopping

Test Clues

Law enforcement personnel are trained to look for clues as to intoxication as the suspect proceeds with the test.  Among the signs the officer is looking for are beginning the test too soon, the inability to walk heel-to-toe or in a straight line, taking the wrong number of steps, difficulty turning and relying on arms for balance.  In all, there are nine clues as established by NHTSA protocol, and if the officer observes two separate clues, the suspect is classified as having a BAC of higher than 0.01.

Challenging the Test Results

• Officer instructions; for the test results to be valid, the officer must thoroughly explain to the suspect what is expected and physically demonstrate proper technique.
• Test standards; there must be no danger of the suspect falling, so the officer is to ensure the test is conducted on a hard, dry, non-slippery and relatively level surface.  The designated area must permit for nine steps and a turn-around, and it must be sufficiently illuminated so that suspect is able to adequately see.
• Individual factors; even if the proper test protocols are adhered to, there can be reasons why the suspect does not perform well other than based on the consumption of alcohol.  For instance, elderly people may have difficulty with the test, as may either overly small or obese individuals.  Additionally, any number of physical or mental impairments can skew the test results.  Also, distractions, such as performing the test too close to a roadway or inappropriate attire can make the test difficult to take.