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Types of Field Sobriety Tests in California DUIs

Field Sobriety test
Types of Field Sobriety Tests in California DUIs

Types of Field Sobriety Tests in California DUIs

No one plans on getting arrested for a crime. While being accused of driving under the influence of drugs or alcohol can be frightening and stressful, it's crucial to stay as informed and levelheaded as possible to avoid jeopardizing your future during a DUI traffic stop.

Field sobriety tests, or FSTs, are a common procedure during DUI stops to determine the driver’s intoxication or BAC level. In California, a blood alcohol concentration (BAC) level of 0.08% or higher is illegal and can result in DUI charges. Having a basic understanding of the legal processes and procedures involved in a traffic stop is necessary to assert your rights and avoid life-altering mistakes that may lead to a conviction in criminal court.

Keep reading to learn more about common types of field sobriety tests and your rights as a California driver during a DUI traffic stop.

What Is a Field Sobriety Test (FST)?

A field sobriety test (FST) is a roadside exercise used by law enforcement during DUI traffic stops to determine whether or not a driver is intoxicated or impaired. FSTs are designed to measure physical coordination, balance, and cognitive ability.

For an FST to be considered valid and reliable evidence in court, the tests must be conducted according to the National Highway Traffic Safety Administration (NHTSA) guidelines, in which the requirements for non-standardized and standardized field sobriety tests (SFSTs) can be found.

Are California Drivers Required to Consent to FSTs?

No. Under California law, drivers are not legally required to consent to a field sobriety test by a law enforcement official. This means that you can decline to perform roadside exercises without facing legal penalties for your refusal.

However, this isn't information that police officers are likely to volunteer or provide, making it all the more important for vehicle operators to have a clear understanding of their rights on California roads and highways.

Common Types of Field Sobriety Tests

Generally, field sobriety tests (FSTs) in California can be classified under one of the following categories:

  • Balance Tests
  • Coordination Tests
  • Mental Agility Tests
  • Eye Tests

Standardized Field Sobriety Tests (SFSTs)

While dozens of field sobriety tests can be used by law enforcement officials, NHTSA has only validated 3 field sobriety tests as “standardized.” Commonly known as SFSTs, standardized field sobriety tests in California include:

The Horizontal Gaze Nystagmus (HGN) Test

The horizontal gaze nystagmus (HGN) test is a standardized field sobriety test used by California police officers to see if someone is driving while under the influence of drugs or alcohol. The officer will ask the driver to follow an object, like a pen or a flashlight, with their eyes and watch how smoothly they can do it. If the driver has trouble following it correctly, they may be arrested for DUI.

The Walk-and-Turn (WAT) Test

The walk-and-turn (WAT) test is a type of standardized field sobriety test used in California to help police officers determine whether a driver is operating a vehicle under the influence of drugs or alcohol. To conduct this test, the officer will ask the driver to walk heel-to-toe in a straight line for a designated number of steps while keeping their arms at their sides and complying with the law enforcement official’s instructions.

The One-Leg Stand (OLS) Test

The one-leg stand (OLS) test is used by law enforcement in California to determine if someone is driving under the influence of alcohol or drugs. During this standardized field sobriety test (SFST), the law enforcement official will ask the driver to stand on one foot and raise their other foot 6 inches above the ground. The driver will be asked to count out loud for 30 seconds without making any mistakes.

If the driver cannot perform this SFST correctly as per the police officer’s instructions, they can be arrested and face DUI charges in criminal court.

Non-Standardized Field Sobriety Tests

Non-standardized field sobriety tests (FSTs) are not approved by NHTSA as measures of intoxication, but can still be used by law enforcement officers in California during DUI traffic stops. These tests typically measure physical coordination, balance, and cognitive ability, although their validity as evidence in criminal court is typically less reliable than the SFSTs with NHTSA approval.

Common types of non-standardized field sobriety tests used by California law enforcement in DUI stops include:

  • Finger-to-Nose Test – One type of non-standardized FST is a finger-to-nose test. During this test, an officer will ask a driver to stand with their feet together and arms extended in front of them before being asked to touch their finger to their nose on command from the officer.
  • Hand Pat Test – This “divided attention” test can also be used to assess intoxication during California DUI stops. It requires the driver to extend one upturned hand in front of them and place their other downturned hand on top. The driver must then use the top hand to pat the bottom hand while counting aloud.
  • Rhomberg Balance Test – The Rhomberg Balance Test is another example of a non-standardized FST in which the driver must close their eyes while estimating 30 seconds before signaling they are finished. In some cases, officers may also ask drivers to count backward or recite the alphabet.

How Accurate Are FSTs in Criminal Court?

It's important to remember that failure to perform any of these field sobriety tests doesn’t result in automatic guilt when it comes to DUI charges. Even if these tests are conducted properly, they still may not accurately measure intoxication.

Many other factors can affect test performance, such as stress, fatigue, and other medical conditions. For this reason, it's important to hire an experienced DUI defense lawyer when facing DUI charges in California, as they can help guide your steps throughout each step of the legal process and fight to reduce or dismiss the penalties against you.

Aggressively Defending Your Rights in the Bay Area

As the Bay Area’s top criminal defense firm, you can count on the Law Office of Nabiel C. Ahmed to defend your rights and restore your freedom. Our passionate criminal defense attorney has handled thousands of criminal cases in California, making him well-equipped to provide the sound legal counsel and guidance you require to obtain a favorable outcome in court.

Whether you’re facing criminal charges for a vehicular offense, internet offense, or other crime in California, turn to a nationally-renowned legal advocate with a proven track record of success. Our team offers consultations to best serve our clients in Oakland and the surrounding areas. Reach out to our office today to learn how our accomplished firm can fight for the second chance you rightfully deserve.

A DUI offense can carry serious penalties if convicted. Call (510) 907-6600 to schedule a consultation with our trusted criminal defense lawyer.