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Standardized Field Sobriety Tests (SFSTs) for California DUIs

When the police pull someone over and suspect the driver may be impaired, the officers generally request the driver to perform some tests on the side of the road. These are known as standardized field sobriety tests (SFSTs). Police, sheriffs, and the CHP use these tests while investigating whether a driver may be under the influence of drugs or alcohol. The three "standardized tests" are only relevant to alcohol and are not relevant to drug DUI cases.

These SFSTs were created after research from the National Highway Traffic Safety Administration (NHTSA). They are supposed to help law enforcement evaluate a driver's level of impairment. The results of these tests can be used as evidence in court. However, there are a lot of problems with these tests that can lead to innocent people getting charged with drunk driving.

What are the Standardized Field Sobriety Tests cops use in California?

There are 3 primary field sobriety tests used by law enforcement in California. These include:


Walk-and-Turn Test

The walk-and-turn test involves a person walking heel to toe, single file, along a straight line. The individual is supposed to take nine steps, then turn around on one foot, and repeat nine steps in the opposite direction. This test is also called the nine-step walk and turn, or the walk-the-line test.

One-Leg Stand

The one-leg-stand test, or OLS, is supposed to measure balance. The individual is asked to raise one leg off the ground at about six inches, keeping both legs straight. While holding that position, the individual is told to count out loud until told to stop.

Horizontal Gaze Nystagmus (HGN) Test

The horizontal gaze nystagmus test is an eye test where an officer looks for an involuntary jerking motion of the eyeball, known as “nystagmus.” This test is done by asking the individual to follow an item such as a pen, flashlight, or a finger back and forth with their eyes. The angle at which the eye begins to demonstrate nystagmus is recorded and the degree of maximum deviation.

Do you have to consent to perform these roadside tests if you are pulled over?

Under California law, drivers are not required to perform field sobriety tests. However, at the time you are standing on the side of the road with a police officer shining a light in your eyes, it may not feel like you have the right to refuse.

The officer is not there to defend you or tell you all your legal rights. Law enforcement may simply give you the instructions to perform the tests, leading you to believe they are not optional. This often starts with the officer shining a light in your eyes and asking you to follow an object back and forth.

Even if you are hesitant to agree to perform any of these tests, the police may imply that you should say yes. Officers may say something like, “what do you have to hide?,” or “if you don't do these tests I'm just going to place you under arrest.”

The police often try to get people with physical or medical problems to do the tests by saying "....I will take that into consideration...". This rarely bodes well for someone being investigated. The police officers are not doctors and are incapable of knowing how a person's physical or medical condition may affect their performance on FSTs.

However, the police can still arrest you with or without these sobriety tests. They are trying to get you to do the tests to use as evidence against you to get you to plead guilty. Unfortunately, these tests are not always fair. Even if you are innocent, the prosecutor can use the evidence of these tests against you in court.

What are the police looking for in a field sobriety test? 

The police are not just looking for whether someone falls over in a roadside test. There are a number of things that officers are trained to look for and record as possible “evidence” of impairment, even if there are innocent reasons for these things. Some of the things police look for in an SFST include:

  • Balance while listening to instructions;
  • Starting an activity too early;
  • Not following all the instructions;
  • Taking the wrong number of steps; or
  • Using their arms to stay balanced.

According to the NHTSA, some tests are “divided attention” tests that require a person to listen to instructions while following the directions. This can be difficult to do for impaired drivers but can also be difficult under stressful conditions, with physical disabilities, or when a driver is distracted on the side of the road by passing cars and flashing lights.

How do you “pass” the tests?

One of the primary problems with these field sobriety tests is that are so many ways to “fail” a test, it may be impossible to “pass” the tests for some drivers. The tests rely on a number of subjective criteria, including officer training, evaluation, the environment, and police misconduct. There are also many things that could cause a completely sober person to fail, including physical conditions, diet, medication, and weight.

Law enforcement officers may not always give the same standardized instructions. After giving hundreds of field sobriety tests, an officer may leave out an important instruction that could cause the driver to fail. Officers may also not fully observe the individual taking the test or just make assumptions about how the individual will perform.

Additionally, people with certain medical or physical limitations can find it difficult to take part in the walk-and-turn test or one-leg-stand test. These tests can be painful or impossible for some people to perform. Even common reactions, like anxiety or nervousness, can be misinterpreted as evidence of alcohol or drug use, even if the driver is totally sober.

East Bay DUI Attorney Defense

Standardized field sobriety tests are used as evidence of impairment in a California DUI. However, you don't have to do these inaccurate SFSTs if you are pulled over. Even if you do these roadside tests, Lynn Gorelick is an experienced East Bay DUI defense attorney has been trained in the administration of the FSTs and can fight for you to throw out this evidence or point out all the flaws with these tests. With over 37 years of DUI experience, Lynn Gorelick understands the law and the science required to fight drunk driving and drug DUI charges. Contact Gorelick Law Offices in the East Bay today. Lynn Gorelick will be happy to speak with you at your convenience 510-785-1444 or 925-847-3006 or email her at [email protected]

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