Field Sobriety Tests

Not every city has an excellent public transportation system for returning residents to their homes following a night out. However, self-driving home after a night of drinking because your designated driver abandoned you will not win you points with a judge. If you see those unmistakable red and blue lights in your rear view mirror after drinking, you’re probably curious about the types of tests officers use to determine if you’re driving while impaired. The following section will discuss field sobriety tests.

The Fundamentals of Field Sobriety Tests

Field sobriety tests, also known as roadside sobriety tests, are used to enforce DUI laws and are typically used in conjunction with Breathalyzer tests. Typically, a police officer will administer a three-part field sobriety test following a traffic stop in which the officer suspects the motorist may be intoxicated or otherwise impaired. These tests enable an officer to observe a suspect’s balance, physical ability, and level of attention, among other factors, in order to determine whether the suspect is driving while intoxicated.

Officers record the suspect’s performance on a field sobriety test; such tests have generally been upheld on appeal in DUI cases. All field sobriety tests are designed to determine whether a police officer has probable cause to arrest someone for driving while intoxicated.

Field Sobriety Tests That Are Standardized

The National Highway Traffic and Safety Administration’s (NHTSA) Standardized Field Sobriety Test (SFST) consists of the horizontal gaze nystagmus (HGN), walk-and-turn (WAT), and one-leg stand (OLS):

Horizontal Gaze Nystagmus: This term refers to the natural jerking of the eye that occurs when the eye is directed to the side. However, when someone is intoxicated, this jerking (or nystagmus) is exaggerated. Officers look for three indicators of impairment in each eye: an inability to smoothly follow a moving object; distinct eye jerking when the eye is at its maximum deviation; and eye jerking within 45 degrees of center.

The purpose of this test, which is easily performed by the majority of unimpaired individuals, is to assess the suspect’s ability to complete tasks with divided attention. This is administered by instructing the suspect to take nine steps, heel to toe, in a straight line; turn on one foot; and then repeat in the opposite direction.

Suspects are instructed to stand with one foot approximately six inches off the ground and count for thirty seconds. Swaying while balancing, balancing with one’s arms, hopping, or putting one’s foot down all indicate potential impairment.

According to a 1998 study cited by the NHTSA, the three components of the SFST accurately indicate alcohol impairment in 91 percent of all cases and 94 percent of cases when explanations for some of the false positives are accepted. Suspects who fail the field sobriety test are typically subjected to a breathalyzer test to determine their blood alcohol concentration prior to arrest.

Field Sobriety Tests That Are Not Standardized

Other non-standardized field sobriety tests may include the following: standing with feet together and tipping the head backwards; counting the number of fingers raised by an officer; reciting the alphabet; counting backwards; standing and leaning back to look up at the sky with arms to the side; or closing the eyes and touching the nose with a finger.

Speak with a Lawyer to Gain a Better Understanding of Field Sobriety Tests

The field sobriety test is one of several techniques that police officers use to establish probable cause for a DUI arrest. However, if the investigation was not conducted properly, there is a possibility that the charges could be dropped in certain circumstances. It is critical to obtain critical feedback from a legal professional for this and other reasons. Speak with an experienced DUI attorney near you today to learn more.