The charge of DUI requires proof that a driver was affected by alcohol consumption. It means that evidence must be presented that a driver’s physical or mental functions were affected and should not be driving a car. The roadside tests known as field sobriety tests are the horizontal gaze nystagmus, walk and turn, and the one leg stand the test. Sometimes they will add the preliminary breathalyzer test.
1. Horizontal Gaze Nystagmus Test
Horizontal Gaze Nystagmus means the involuntary twitching of the eyes as it gazes to the side. According to the NHTSA, as the alcohol concentration increases, a person’s eyes will bounce as it moves back and forth. There are three parts to these tests; looking for smooth pursuit, the surge of uncontrolled movements before 45 degrees, and sustained and distinct uncontrolled movements at maximum deviation.
The maximum score anyone can reach is 6/6; this means all the clues would be present in both eyes. The test is the most relied on, though there are other causes of Nystagmus which has nothing to do with intoxication.
2. Walk and Turn Test
Walk and turn is a divided attention test that shows whether you’re capable or not of the same physical and mental abilities that a person needs to drive a car safely. You’re required to take nine heels to toe steps on an imaginary straight line, and shuffle around in a directed manner, and then take nine heel-to-toe steps back to the starting point.
There are eight different clues the officer is checking out for, and some include: raising your arms over six inches, performing an improper turn, not stepping heel to toe, not being able to maintain balance, an incorrect number of steps, and starting the test too soon.
3. One Leg Stand Test
One leg stand test is the final validated test. While rising one of the legs at about 6 inches off the ground, you are to count out loud for thirty seconds. The test has four clues, and the scoring of 2 equals a failing score. The clues are wobbling, hopping, putting your leg down, and balancing with your arms.
4. Portable Breath Test
After the field sobriety tests, you’ll usually be required to take a breathalyzer, this, however, is not admissible in court, and the officer is obligated to inform you.
Am I required to perform these tests?
The tests are voluntary; this means you can refuse to perform these tests. However, if you decide not to complete the test, it’ll be used as evidence that you decline because you are guilty of DUI. Whether you perform the field sobriety test or not, the police officer has already decided to arrest you; they just need more evidence they will later use to try and convict you. If you refuse to perform the test, an experienced lawyer can easily rebut that argument.