Why Sober Drivers Fail Field Sobriety Tests


Being arrested for a crime you didn't commit is anyone’s worst nightmare. Unfortunately, by submitting to a field sobriety test, this fear can become a reality. It's just as easy for a sober driver to fail as an impaired driver. Given this reality, submitting to one might be a mistake.

Despite what police officers may attempt to make you believe, you’re not required by Oregon law to submit to a field sobriety test.

In this month’s post, we’ll outline what field sobriety tests are, why they are problematic, and what you should do when pulled over and are being pressured by a cop to take one.



What Are Field Sobriety Tests?

Field sobriety tests (FSTs) are nationally recognized tests designed to help law enforcement officers identify drivers suspected of driving under the influence. 

While blood alcohol concentration (BAC) tests are absolute in their determination of an intoxicated driver, not all police cars are equipped with the capability to administer the test. This means in order to determine if a driver is scientifically considered drunk, an officer has to take them down to the police station. To avoid this delay, the field sobriety test is often used. 


The Components of a Field Sobriety Test

A field sobriety test has three components. In theory, these are designed for sober drivers to easily pass and for impaired drivers to clearly fail. As we’ll see, however, this is not always the case.

Throughout each of the tests, law enforcement officers will be looking for slip ups, or clues, indicating impairment. Display enough of these “clues” and you will be placed under arrest. 

Unfortunately, the line between passing and failing these tests are completely subjective and open to the interpretation of a suspicious officer.

Horizontal Gaze Nystagmus Test 

The Horizontal Gaze Nystagmus (HGN) test is used to identify a nystagmus, or involuntary twitch in your eye, as an officer moves a stimulus (such as a pen or finger) across your face. 

All eyes will have a nystagmus when the eye is at an angle greater than 45 degrees. Those with alcohol in their system, however, can have it happen before 45 degrees. Cops will be on the lookout for this as they are administering the test, and will take this as a clue if it happens.

While the HGN test is the most scientific of all of the FSTs, it is still open to interpretation and highly subjective. While alcohol is shown to cause nystagmus, it’s not the only cause. This makes the reliability of the test shaky at best. 

The Walk and Turn Test 

The walk and turn test is a divided attention field sobriety test. It is used to determine whether a suspect can complete tasks with divided attention. 

During the test, an officer will instruct you to walk nine steps heel to toe in a straight line. Once you reach nine steps, you'll then have to turn on one foot and head back the other direction. The police officer will be taking note if you…

  • Are able to maintain balance while listening to the officer's instructions

  • Start before the officer has completed instructions

  • Stop to regain balance while walking in the line

  • Are maintaining heel to toe walking throughout

  • Are using your arms to maintain balance

  • Maintain balance while turning half way through

  • Take the correct number of steps

If he notices you do any of these, it will be taken as a “clue” you are under the influence. 

The One Leg Test 

Like the walk and turn test, the One Leg Stand is designed to test if you’re able to complete tasks with divided attention. 

Standing with one foot approximately 6 inches off the ground and your foot pointed, you must keep perfect balance while counting to 30. Your arms are to remain at your side and you must be looking down the entire time. The officer will be on the lookout for if you...

  • Put your foot down before the test is complete

  • Sway over the course of the 30 seconds

  • Hop while attempting to maintain balance

  • Use your arms to help maintain balance

Again, any of these will be taken as a “clue.”



Why Might You Fail a Field Sobriety Test?

It’s important to remember that field sobriety tests are designed to make you look impaired-- whether you are or not. While the walk and turn test may seem like just a balance test, the office is going to be purposefully trying to confuse you in an attempt to get a clue.

The fact of the matter is any police officer who pulls you over and is attempting to get you to take a field sobriety test is suspicious you are drunk. They are going to do whatever they can to conform these suspicions. Field sobriety tests are a way for them to do that.

Remember, field sobriety tests are not objective tests.

All three tests take into consideration the subjectivity of the police officer in how they thought you performed. Something small one officer doesn’t notice, another might.

When submitting to a field sobriety test, your criminal record is in the hands of a police officer who’s under the assumption you are drunk, even if you’re not.



Should You Submit to a Field Sobriety Test?

This question has a simple answer: No!

Unlike refusal of a BAC test, which will automatically net you a 1 year license-suspension , there is virtually no consequences for failing to submit to a field sobriety test.

Police officers know you don’t need to take the test, but will try to get you to submit to one anyways. 

The Rohrs Admonishment 

An officer will often cite the The Rohrs Admonishment as a reason you should take a field sobriety test. They will likely be purposefully vague on the details of what this means.  

The Rohrs Admonishment states if you refuse a field sobriety test, the refusal can be used against you in court. It does not say it will not trigger a guilty verdict or immediate revocation of your license.

All this means is the prosecution will say you denied a field sobriety test in court. Luckily, any experienced defense attorney will be able to get past this in court and make the effects of this denial negligible. 



What Will Happen After I Refuse or Take a Field Sobriety Test?

No matter what you decide, if asked to submit to a field sobriety test, you are likely headed to the police station. 

We have different advice, depending on if you decide to take the field sobriety test or not. 

If You Take It

Even a sober driver in perfect conditions is more likely than not to fail. 

If you fail, you’ll then be brought down to the station, and this failure of a field sobriety test will be used as evidence against you in their case for a DUII. They will likely also give you a BAC test. 

If You Don’t Take It

If you don’t take the FST, you will still likely be headed to the police station. 

Once there, you will be given the opportunity to take a BAC test. As already stated, if you refuse this test you will be given an immediate 1-year suspension. 


Were You Charged with a DUII? 

Were you charged with a DUII? Contact me today at (503) 227-3800 to learn your options. Your consultation is always free and confidential. 

Adam Greenman
Adam Greenman has been a trusted criminal defense and personal injury attorney in Portland for over 15 years. A graduate of Lewis and Clark School of Law and an experienced former prosecutor, Adam is a proud member of the Oregon State Bar Association, Oregon Trial Lawyers Association, and the Oregon Criminal Defense Lawyers Association. He is known for providing personal, one-on-one attention to clients.