The walk and turn test is one of three field sobriety tests that have been “standardized” by the National Highway Traffic Safety Administration. The three are:
The suspect stands in a heel-to-toe fashion with arms at the sides while a series of instructions are given. Then, the suspect must take nine heel-to-toe steps along a line, turn in a prescribed manner, and take another nine heel-to-toe steps along the line. All of this must be done while counting the steps aloud and keeping the arms at the sides. The suspect should not stop walking until the test is completed.
The officer is instructed to give the test as follows:
The officer is also given the following instructions:
The Walk and Turn test has eight clues of impairment. Two clues apply while the suspect is standing heel-to-toe and listening to the instructions:
The other six validated clues apply during the walking stage of the test. They are:
Two or more clues classify the suspect’s blood alcohol concentration (BAC) as above a 0.10%.
The officer is warned that this test requires a designated straight line and should be conducted on a reasonably dry, hard, level, non-slippery surface.
In addition, the officer is told that original research indicated that individuals over the age of 65, and those with back, leg or middle ear problems had difficulty performing the test. Subjects wearing heels more than 2 inches high should be given the opportunity to remove their shoes.