NCJ Number
101584
Date Published
Unknown
Length
22 pages
Annotation
This training manual describes the administration of three reliable roadside tests for alcohol-impaired driving: the horizontal-gaze test, the walk-and-turn test, and the one-leg-stand test.
Abstract
The horizontal-gaze test, the most accurate of the three, is based in the nystagmus phenomenon, which is an involuntary jerking of the eyes as the body attempts to maintain orientation and balance. As persons become more and more intoxicated, the eye jerking become increasingly prominent to the point that levels of alcohol consumption can be approximated by observing the nystagmus. The walk-and-turn test involves the suspect's assuming a heel-to-toe standing position on a designated line with arms hanging by the sides while receiving additional instructions from the officer. The suspect is instructed to take nine heel-to-toe steps down the line, turn around, and take the same number of steps back, all while watching the feet and counting the steps. Scoring based on proficiency in completing the test approximates the level of alcohol in the blood. In the one-leg-stand test, the suspect stands with feet together and arms down at the sides. As one leg is raised about 6 inches from the ground, the suspect counts to 30. Scoring on proficiency indicates blood alcohol level. This manual provides detailed instructions for officers in administering the test, including the scoring, and notes the limitations of each test.