The problem with field sobriety tests

On Behalf of | Feb 23, 2024 | DUI |

You’ve likely seen people being put through the roadside field sobriety tests on TV or in real life. The tests generally appear straightforward. However, when it’s you who’s been stopped, this process can inspire anxiety that can make them extremely challenging, compounded by passing cars, bright lights, and intimidating police officers.

Some of these tests, which are separate from the breath test used to measure blood alcohol content (BAC), assess motor skills and balance that typically suffer when a person is under the influence of alcohol and/or drugs. The three primary tests are the:

  • Walk-and-turn: walking heel-to-toe on a straight line, turning in place and walking the opposite direction
  • One-leg stand: balancing on one leg
  • Horizontal gaze nystagmus (HGN): following an object like a finger or small flashlight with your eyes as it’s moved back and forth to determine how soon the eyes start to jerk

You may also be asked to touch your finger to the tip of your nose or recite the alphabet. However, the first three are the most commonly used, as they are considered to be the most reliable.

Performance may have nothing to do with sobriety

Unlike breath tests (which also aren’t 100% reliable), performance in these field sobriety tests is subjective. Some officers may be more lenient than others. Further, many people simply aren’t physically capable of doing some of them (like the walk-and-turn and one-leg stand) under any circumstances.

The HGN test has been determined to be the most accurate (77%) as opposed to under 70% for the other two. That’s still not a reliable indicator of sobriety. Anything from an eye condition to too much caffeine can cause you to “perform poorly” on it.

So why do officers still use them? Like anything else they observe during the stop, the tests can help officers assess but not definitively prove whether someone is under the influence. It also gives them more time to interact with the person they’ve pulled over and develop probable cause for arrest.

Can you refuse to do any or all of these tests?

It’s important to remember that unlike a chemical test (of breath, urine or blood), there are no direct consequences for refusing to do any or all of these field sobriety tests. Certainly, if you know you can’t do some or all of them because of your own physical limitations, tell the officer.

While police can’t arrest you for refusing to take the tests (assuming you do so respectfully), they can still arrest you if they have probable cause to believe you were driving under the influence. If that happens, it’s wise to get legal guidance as soon as possible to protect your rights.