Field sobriety tests are conducted to determine the level of intoxication of a person, that is, if they are under the influence of alcohol or drugs. SFST stands for Standard Field Sobriety Tests and were developed by the National Highway Traffic Safety Administration (NHTSA). These tests are typically administered roadside after an individual is stopped and suspected of being under the influence.

Types of Field Sobriety Tests

Law enforcement employs an arsenal of equipment and tests to determine how intoxicated a driver may be. A common method of testing that has been used since the advent of drunk driving laws are FST (Field Sobriety Test). Some common FSTs are HGN (Horizontal Gaze Nystagmus), one-leg-stand, walk-and-turn, finger-to-nose, and counting backwards. Each test has its own advantages and disadvantages. However, they all share the same disadvantage of relying on basic physical abilities that not all people posses.


As it sounds, the suspect will stand on one leg. If there is any swaying or imbalance the suspect could be charged with DUI. The test may be inaccurate if the driver is overweight, affected by prescription drugs, has poor night vision or is wearing high heel shoes.

Horizontal Gaze Nystagmus (HGN)

The HGN test is perhaps the most widely accepted and scientifically approved. The police officer will have the subject follow an object (such as a pen) while the officer checks for signs of intoxication, lack of smooth pursuit, deviation, etc. Prescription drugs and various medical conditions can also influence eye nystagmus.


The suspect will take 10 steps (heel to toe), then turn and repeat the 10 steps back. The officer will be checking to see if the driver is following directions properly and able to perform the physical actions without any tripping or swaying. Again, the test is making the assumption that the suspect does not have any physical condition that could impact the results.

Finger-to-Nose, Counting Backwards and Reciting the Alphabet

To perform the finger-to-nose test, the driver will extend each arm and touch the tip of their nose with their index finger. Missing the tip of the nose may result in further testing or DUI charges. Counting backwards or reciting the alphabet could be complicated by the pressure of the situation, potentially nullifying any negative results.

Rhomberg Test

As more and more Georgia Police Officer attend DRE training, the Rhomberg (or Modified Rhomberg) is becoming more popular. Again there has been no correlation between observations made by police officers using the Rhomberg Test and Impairment. In this test, the driver stands, feet together, and leans the head back to look up at the sky while holding their arms out to the side. The Police Officer then asks the driver to close his eyes and to estimate the passage of 30 seconds. Here the police officer looks for eyelid tremors, inability to estimate the passage of time, and swaying by the driver.

Test Refusal

Well-trained impaired driving lawyers know that every one of the so-called field sobriety tests used by police are not scientifically correlated to how to calculate blood alcohol level of that driver. This is why you should refuse any sobriety test offered by an officer investigating you for drunken driving or drugged driving.

Field sobriety exercises, or tests, are totally voluntary and there is no penalty for not doing them. The police don’t tell you they are voluntary. They don’t even tell you that you have an option. When you do these evaluations while you are already frightened and your adrenaline is flowing. When you’re standing on the sloped highway sometimes with pebbles and rocks on it and blue lights are going in the background. It is not an ideal condition to be doing agility exercises.

These tests are designed for you to fail. They’re going to be subjectively graded. You couldn’t pass them on carpeted floor in an air conditioned room much less on a sloped highway. Don’t attempt them. The best you can do is be reasonable and be polite. Say, “I’d like to speak to an attorney, I’m not familiar with this process, and can I call an attorney? I have his or her number.”


EVERY knowledgeable DUI / DWI attorney will tell you to NOT attempt these police tests. That is because peer-reviewed scientific studies have concluded that the SFSTs are “designed to fail”. Here are the five most significant deficiencies in all NHTSA field sobriety tests:

  • Before starting its statistical analysis in 1977, no “norms” were established, by age brackets, to know how well totally sober individuals performed.
  • One Texas review of thousands of DWI arrest videos showed that 98% of all officers made errors in the instructions or administration of the SFST police tests.
  • Even when NOT instructed correctly or scored correctly, the police still get to use the 3 test battery against you in court, in some states.
  • Scoring is subjective, and the actual clues are often not captured on video, so the officer’s word is accepted by the jury.
  • Bogus training that teaches officers false, “reliability” numbers based upon the, “validation studies” creates a need to hire an expert witness to refute these lies.