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Are field sobriety tests accurate?

Field sobriety tests are the roadside test police officers ask drivers to complete to demonstrate if the driver is impaired. This includes familiar tests like the one-leg-stand test and the walk-and-turn test, and the less familiar horizontal gaze nystagmus (HGN) eye test.

Many drivers agree to do these tests expecting they will be released after passing the test only to find they “failed,” and are going to be arrested. Unfortunately, these tests are not always accurate. A sober person can “fail” and an impaired driver can “pass” these tests.

If you were arrested on suspicion of a DUI after submitting to field sobriety tests, you may be able to challenge the results of those tests in court. If you have any questions about field sobriety tests in California, talk to an experienced East Bay DUI defense lawyer in your area.

What are the police looking for in roadside DUI tests?

When the police are conducting these roadside tests, they are not just looking for whether you can complete them or not. They have a ranking and scoring system that includes a lot of factors drivers don't know about. This is one of the reasons why these tests can be so inaccurate.

Walk and Turn Test Clues

In the walk and turn test, the clues the officer looks for include:

  • Starting too soon,
  • Stopping too soon,
  • Not putting heel-to-toe
  • Using your arms to balance,
  • Taking too many/not enough steps,
  • Not turning on the line,
  • Stepping off the line, or
  • Losing balance.

One Leg Stand Test Clues

In the one leg stand test, balance is not the only thing being tested. The clues the officer is looking for include:

  • Starting too soon,
  • Hopping on one foot,
  • Lowering the foot too soon,
  • Using arms to keep balance, or
  • Losing balance.

HGN Eye Test Clues

In the HGN eye test, the police are watching the eye to see at what point the eye has involuntary movement, or nystagmus. The police are looking for at what angle the movement starts. This is based on estimating the angle, without the use of a protractor or other device that can actually measure angles.

What makes field sobriety tests inaccurate?

There are a few reasons why these tests are not always accurate. This includes operator error by the police officer, environmental conditions of the surroundings, and the individual driver.

The police take a brief training course to learn how to conduct these standardized field sobriety tests, what to look for, instructions to give, and how to score the tests. If the officer does not give the full instructions, over- or underestimates their angle or count, does not pay attention during the test, or is not clear about anything, the driver can suffer.

Each person performs these tests differently, especially when it comes to balance. Things like clothing, weight, medical conditions, and physical fitness can all affect balance. For example, someone who does yoga regularly may be able to stand on one leg for 10 minutes with no problems. Someone who is overweight and wearing heels may have trouble standing on one leg for even a couple of seconds.

Field sobriety tests are supposed to be conducted under ideal conditions. However, more often, they are conducted at night on the side of a busy road. Speeding cars, bright headlights, flashing police lights, uneven road conditions, and the anxiety of being subject to these embarrassing tests on the highway can make performance more difficult for anyone.

What should I do if the officer asks me to do these DUI tests?

It is ultimately up to you whether or not you want to do these somewhat subjective tests. However, it is important to know that these tests are NOT mandatory. There are no penalties for refusing to do these roadside sobriety tests.

These tests are generally used by police and prosecutors to justify the arrest. An officer can rely on the test results to give them the probable cause to make a drunk driving arrest. However, without these test results, the officer has to rely on other factors and may not have enough evidence to justify an arrest.

Talk to your DUI defense attorney about your case, the best defenses available, and how to fight to get your charges reduced, dropped, or take your case to court.  

Challenging DUI Field Sobriety Tests in California

East Bay DUI lawyer Lynn Gorelick has more than 35 years of DUI experience and understands an inaccurate field sobriety test can make it appear like you were guilty of drunk driving even if you were not impaired. Lynn Gorelick can challenge the arrest based on field sobriety tests. Contact California DUI lawyer Lynn Gorelick today.

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