There are many different types of field sobriety tests. Three such tests have been“standardized” by the National Highway Traffic Safety Administration:
Other tests are not standardized, but are still commonly used by many officers. These tests include:
The finger to nose test, which is administered in a variety of formats, generally requires the subject to close their eyes and then touch the tip of their nose with the tip of their index finger, alternating hands.
The National Highway Traffic Safety Administration research project revealed that the finger to nose test (along with the Romberg test) only reflects the presence of alcohol, and does “not increase the predictive ability of testing.”
The alphabet test requires the subject to recite part of the alphabet (e.g., starting at a letter other than A and stopping at a letter other than Z). Alternatively the entire alphabet is required to be recited or written down. Contrary to urban legend, the alphabet test does not require the subject to recite the alphabet backwards.
The count down test requires the subject to count aloud numbers in reverse. For example count backwards from 90 to 70.
Sometimes the officer will have the subject stand with one foot in front of the other in a heel to toe position when performing the alphabet test or the count down test.
The finger count test requires the subject to touch the tip of the thumb to the tip of each finger on the same hand in a particular order while counting (e.g., “one, two, three, four—four, three, two, one).
A research study has concluded that handwriting changes can be observed at any level of alcohol. However, “none of the alterations in handwriting can be attributed to the effects of alcohol intake alone.”
However, not all studies indicate that handwriting may be a reliable indication of alcohol concentration. In one study, deterioration in handwriting was charted for 35 men and women who had provided handwriting samples prior to the consumption of alcohol, and again after the drinking period had ended. The researchers concluded that handwriting could not be used in any way to measure accurately the blood alcohol concentration of a writer.
The hand pat has the person taking the test place one hand palm up and in front. The other hand is placed on this hand with the palm down. The top hand then pats the bottom hand once and is then rotated 180 degrees to pat the bottom hand with the back of the top hand. The test continues until the officer tells the subject to stop. The subject is told to increase the speed of the rotation of the hand during the test.
Some consider the test to be a failure-designed test because as the speed increases most people will eventually double pat or roll or chop their hand instead of patting the hand one time cleanly on each rotation as the test requires.
Like the hand pat, picking up coins also involves the use of the hands rather than balancing on a person’s legs. This has the advantage of not having to use the legs when a subject tells the officer during the pre-field sobriety test questioning that he or she has a bad back, leg or knee. Like the hand pat, the test suffers from not having been scientifically validated as an accurate prediction of sobriety. The test has the subject pick up with one hand several coins on a flat surface like the hood of the car. It is rarely used.