A police officer may pull you over for various reasons. You might get pulled over for speeding, reckless driving, running a red light, or an equipment violation. But, one of the most common reasons is the suspicion of drunk driving. There are many indications that can help a police officer spot an impaired driver. The following signs can reveal if someone is driving under the influence: driving at unreasonably low or excessively high speeds, ignoring traffic signs, driving without lights, following another car too closely, changing lanes frequently, driving with turn signals on, making extremely wide turns, and so on. So, when an officer notices some of these signs, he/she will pull you over to check your blood alcohol content. You are probably going to be asked to do a field sobriety test first, and if it’s not conclusive, the officer will administer a breathalyser test. Breathalyser tests are mandatory, but you can refuse to do a field sobriety test.
Although field sobriety tests are somewhat controversial, as they are based on the police officer’s subjective opinion on how drunk a person is, they are still conducted in the U.S. There are three standardized tests: the one-leg stand, the walk and turn, and the horizontal gaze nystagmus test.
During the walk-and-turn test, you have to take nine heel-to-toe steps along a straight line. After you’ve taken the nine steps, you have to turn and take another nine steps to get back to the starting point. If you can’t touch heel-to-toe, or you use your arms to maintain balance, or you take more or less steps than what the officer has instructed, it will be considered that you have been driving under the influence of alcohol.
In the one-leg-stand test, you have to try and stand on one leg for 30 seconds, while counting aloud. Your other foot has to be six inches off the ground. You will fail the test if you try to balance with your arms, or if you put your foot down.
These are the standardized tests, which are conducted most often. Apart from that, there are several other tests that you may be asked to do. So, you may have to count backwards, or recite the alphabet. There is also the finger-to-nose test, where you have to close your eyes and try and touch your nose.
So, even though the validity and reliability of field sobriety tests are disputed, drivers have to be aware that many officers use them to determine if someone has high blood alcohol content and respond accordingly to the cops.