Impaired driving is dangerous. But law enforcement has come up with a streamlined way to check if you are okay to drive.

After a night of drinks, the last place you want to be is on the side of the road trying to prove you can walk in a straight line. But if you misjudge your level of sobriety or have to take part in a traffic stop at a DUI checkpoint, it’s worth knowing what the Standardized Field Sobriety Test (SFST) entails.

There are essentially three separate tests are part of the SFST, including:

  1. One-leg stand test: The name of this test is fairly self-explanatory. An officer will require an individual to step out of their car and stand with one foot about six inches off the ground while counting for 30 seconds. The officer will note whether the individual is struggling to keep balance.
  2. Horizontal gaze nystagmus (HGN) test: The purpose of the HGN test is to see if an individual’s eyes are involuntarily jerking as this can be an indication of impairment. A police officer will test this by having the suspected drunk or drugged driver follow a moving object, like a pen or flashlight, with their eyes in a horizontal fashion.
  3. Walk-and-turn test: The last standard test requires a driver to take nine heel-to-toe steps in a straight line, turn around and take another nine steps. The officer will observe both the driver’s balancing ability and ability to follow the detailed instructions.

There are also some non-standardized tests an officer might incorporate into the traffic stop that could involve counting or reciting a portion of the alphabet.

Even sober people have been known to fail these tests due to health conditions or sheer nervousness. Therefore, it’s crucial to take each test seriously and understand your right to refuse taking the tests.