If a driver in Pensacola, Florida, is pulled over for a DUI, an officer may conduct field sobriety tests. The National Highway Safety Traffic Administration has made three field sobriety tests standard.
Standard field sobriety tests
The horizontal nystagmus gaze test checks for DUI by having the driver follow an object, such as a pen. The officer watches each eye for smooth following, involuntary jerking at 45 degrees, and maximum deviation, or when the eye reaches full range. Each eye is worth three cues each, which equals six cues, and failing three or more may mean failure.
The walk-and-turn test instructs the driver to take nine heel-to-toe steps in a straight line and repeat in the other direction. The officer checks the driver for six cues, including staying on the line, using arms for balance, and listening skills. If a driver misses two or more cues, they fail because it usually indicates a BAC of .10 or higher.
The one-leg stand test asks the driver to stand on one leg six inches from the ground and hold it for 30 seconds. The officer checks for four clues, which include swaying and hopping, and drivers who miss two or more cues commonly fail this test.
Accuracy of field sobriety tests
While the NHTSA recommends these three tests based on scientific research, their accuracy is still debated. The walk-and-turn test is 68% accurate, the one-leg stand test is 65% accurate, and the horizontal gaze test is 77% accurate.
Neuroglial conditions, physical problems, uneven terrain, age and weight can make the tests hard to pass for a sober driver. For example, the flu or an ear infection can cause sober drivers to fail the horizontal gaze nystagmus test.
Getting charged with drunk driving doesn’t always mean guilty. The driver may be able to defend against charges with knowledge of the law and the science of sobriety tests.