The One Leg Stand Test

The One Leg Stand Test

The One Leg Stand test requires the driver to stand with arms aside.  The driver is told to raise and hold one leg at least six (6) inches off the ground and count out loud for thirty (30) seconds.  The time period is important because National Highway Traffic Safety Administration research has shown that drivers with a blood alcohol concentration above .10 can maintain balance for up to twenty five (25) seconds but rarely for thirty (30) seconds.

The One Leg Stand test requires adequate light and is not designed or valid a driver sixty five (65) years or older, or for drivers more than fifty (50) pounds or more overweight.  It’s also not valid for drivers with leg problems or inner ear disorders.

While administering the One Leg Stand test the officer must:

(1)  Instruct the driver to stand with his feet together and his arms at his sides.  Specifically, the officer needs to demonstrate the stance.

(2)  Instruct the driver not to begin the test until told to do so.

(3)  Ask and make certain the driver understands the instructions.

(4)  Explain that when told to start, the driver must raise one leg, either his left or right, approximately six inches off the ground with toes pointed out.  Specifically, the officer needs to demonstrate the stance.

(5)  Inform the driver to keep both legs straight, arms aside, while holding the position long enough to count out loud for thirty seconds by “one thousands”, or until told to stop.  Additionally, the officer must demonstrate the stance and the counting method.

(6)  Remind the driver to keep both arms aside throughout the test while also keeping an eye on the raised foot.

(7)  Confirm that the driver understands the instructions and how to perform the test.  Only then can the officer instruct the driver to begin.

(8)  Observe the driver from three feet away while remaining “as motionless as possible.” If the driver puts his foot down, the officer must instruct him to pick it up and resume counting from the point it touched the ground.  If the driver counts very slowly, the officer must terminate the test after 30 seconds.  Conversely, if the driver counts too quickly, the officer must make him continue until told to stop.

The One Leg Stand test has four (4) scoring clues which the officer must score if the driver:

(1)  Sways side-to-side or back-and-forth while maintaining the one-leg stance.

(2)  Moves his arms six inches or more from his sides to maintain balance.

(3)  Hops to maintain the one-leg stance.

(4)  Puts his foot down one or more times during the thirty seconds.

Finally, if the driver either can’t do the test or puts his foot down three (3) or more times, the officer must record the results as if all four (4) clues were scored.