Types of DUI Field Sobriety Tests

Field sobriety tests are used to assess DUI.

Types of DUI Field Sobriety Tests

Field sobriety tests (FSTs) are utilized by law enforcement officials when pulling over drivers suspected of DUIs. Three tests are specifically approved by the National Highway Traffic Safety Administration, a component of the U.S. Department of Transportation dedicated to achieving the highest standards of excellence in motor vehicle and highway safety. Only formally trained police officers are authorized to perform these Standard Field Sobriety Tests, as approved by the NHTSA.

Field sobriety tests must be consented to by the offender. Unlike chemical/blood tests completed at a police station after arrest, field sobriety tests are not required. In fact, defense attorneys advise against any person consenting to undergo FSTs, as they are designed to be difficult to perform satisfactorily, even for those who are sober. The results of these tests are admissible in court as evidence and almost always work in favor of the prosecution, not the defendant.

Drivers who perform any part of a field sobriety test unsatisfactorily will be asked to take a breath test or chemical test to confirm that blood-alcohol content, or BAC.

The following tests are approved by the NHTSA:

Horizontal Gaze Nystagmus (HGN) Test

While a certain amount is normal in all people, intoxicated individuals have an excessive amount of natural rapid eye movement, or jerking of the eyes, at high degrees of side-to-side gazing. Police officers will ask the driver to follow an object, typically a light pen, with their eyes as they move it from side to side, looking for signs of exaggerated eye jerking.

Walk and Turn Test

In this test, the driver is asked to take nine heel-to-toe steps along a straight line, pivot on one foot, and do the same in the opposite direction. Police officers look for the following to determine impairment:

  • Inability to keep balance.
  • Starting the test too soon.
  • Pausing while walking.
  • Breaking the heel-to-toe connection.
  • Stepping off the straight line.
  • Using arms to aid in balancing.
  • Taking an incorrect number of steps.
  • Turning (pivoting) improperly.
  • Inability to complete the test.

One Leg Stand Test

This test requires the driver to stand on one foot while the other foot is lifted approximately six inches off the ground. The driver must count from “one-thousand-one” and up for thirty seconds, until asked by the officer to return their lifted foot to the ground. Police officers look for the following to determine impairment:

  • Swaying while balancing.
  • Using arms to aid in balancing.
  • Hopping.
  • Putting the raised foot down prematurely.

As these tests are so easy to “fail” regardless of sobriety or intoxication, there can be many defenses to them, including medical conditions, disabilities of any kind, age, injury, medication, ear conditions, landscape, footwear or clothing, fitness level, weather, and eye conditions, among others.

If you have been pulled over for a DUI and performed field sobriety tests of any kind, call Rideout Law Group right away for your best defense.



With offices in Lake Havasu City and Scottsdale, our firm serves the entire state of Arizona, with a particular focus on criminal defense, family law, and juvenile cases.

Our goal is for the best outcome for your criminal case, which can include:

  • charges that are reduced or dropped.
  • top experts reviewing your case.
  • aggressive negotiations with the prosecution for plea bargains.
  • fines or probation in lieu of jail time.

At Rideout Law Group, our attorneys are able to expertly examine the evidence in your case to provide a strong strategy for argument that leads to an outcome that is most favorable to you. We have experience in all types of criminal cases for both adults and juveniles, with positive outcomes both in plea negotiations as well as jury trial settings.

Call us today for a free consultation at 480-584-3328.

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