If an officer thinks you are drinking and driving, he will ask you to step out of your car and perform a few field sobriety tests.
(Note that you have the right to refuse any or all field sobriety tests in Massachusetts. See my post: Stopped for Drunk Driving in Massachusetts? Know Your Rights.)
One of these tests is the “walk and turn” also known as the “nine-step walk and turn.”
It requires you to perform mental and physical tasks simultaneously–something most drunk people can’t do well.
To begin the officer will ask you to stand on a line (real or imaginary) with your feet in a heel-to-toe position and your hands down at your sides.
While you’re in this “instructional position” the cop will explain the test.
When he says “go”, you are to take nine steps heel-to-toe on the straight line. Count each step out loud. On the nineth step keep one foot on the ground and turn by taking small steps with your other foot. Then walk nine steps back, counting as you go.
The first stage of the test requires you to (1) maintain balance in the “instructional position” and (2) comprehend the officer’s directions.
Next you’ll be asked to perform the walk and turn test. Again, you must perform both a physical task (walking/balancing on the line) and a mental tasking (remembering instructions and counting out loud).
When you finish the test, the officer will note the number of impairment “clues” he observed.
There are 8 potential clues:
- losing balance during the instructional stage,
- starting too soon,
- stopping during the test,
- failing to touch your heels to your toes,
- stepping off the line,
- raising your arms for balance,
- turning incorrectly,
- taking an incorrect number of steps.
Two clues or more indicates a blood-alcohol content above the legal limit (0.08 BAC). The test has a 79% accuracy rate, according to the National Highway Traffic Safety Administration (NHTSA).
The walk and turn should be performed on a dry, flat surface. The officer conducting the test should give you plenty of space. He should also remain still to avoid distracting you or throwing you off balance.
Finally, the NHTSA recognizes that persons over 65 may struggle with the walk-and-turn test. Additionally, certain injuries may hinder a driver’s ability to perform the test.