One-Leg-Stand Test: Los Angeles DUI
This post is part of an ongoing series by a Los Angeles DUI Attorney analyzing field sobriety tests and how law enforcement officers in Los Angeles often rely on them to form subjective and unreliable conclusions that a driver is under the influence of alcohol or drugs — thus justifying an arrest under California Vehicle Code § 23152(a) (driving under the influence) or § 23152(b) (driving with a BAC of 0.08% or more).
DUI Investigations in Los Angeles: How They Begin
If a police officer smells alcohol during a traffic stop in Los Angeles, it often triggers a DUI investigation. As any experienced Los Angeles DUI Attorney will tell you, the typical DUI investigation in Los Angeles includes several field sobriety tests (FSTs):
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Horizontal Gaze Nystagmus (HGN)
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Romberg Balance Test
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One-Leg-Stand (OLS)
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Walk-and-Turn (WAT)
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Preliminary Alcohol Screening (PAS) Breath Test
Our standard advice as a Los Angeles DUI Attorney is to politely refuse to perform field sobriety tests and instead agree to a chemical test (blood or breath) at a police station or hospital, as required by California’s implied consent law. These field tests are voluntary, and they are not mandatory under California law.
Focus on One-Leg-Stand (OLS) Test: A Problematic “Standardized” Tool
Let’s take a deeper look at one of the most commonly used FSTs — the One-Leg-Stand Test, which is one of three standardized tests approved by the National Highway Traffic Safety Administration (NHTSA). The other two are HGN and WAT.
According to NHTSA research, the OLS test is only 65% reliable in predicting impairment — which means over one-third of sober individuals can fail this test. That’s a huge margin of error to base a criminal charge on.
During the test, an officer instructs the subject to lift one leg approximately six inches off the ground, keep both legs straight, arms at the sides, and count aloud for 30 seconds. The officer looks for four specific “clues” of impairment:
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Swaying while balancing
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Using arms to balance
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Hopping
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Putting the foot down
If the subject displays two or more of these clues, the officer will fail them and often conclude that their blood alcohol concentration (BAC) is over the legal limit, even if no chemical test has yet been done.
Why This Test is Often Misleading
The Los Angeles DUI Attorney community widely recognizes that this test is flawed for multiple reasons:
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One clue is not enough: NHTSA guidelines clearly state that two or more clues are needed to indicate possible impairment. One clue — no matter how dramatic — does not establish intoxication.
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Test is not suitable for everyone: People over 65, those who are overweight, or individuals with balance, back, or leg issues are not proper candidates for the test. Yet officers often disregard these limitations.
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Highly subjective scoring: Whether a person “sways” or “hops” is left entirely to the officer’s observation, which is not always reliable — especially without dashcam or bodycam footage.
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Real-life conditions differ: Poor lighting, uneven pavement, traffic noise, and stress during police encounters make performance on the OLS test less reliable.
Legal Significance in Los Angeles Courts
Although field sobriety tests are not scientific, prosecutors in Los Angeles Superior Court often use them as key evidence in DUI trials — particularly when chemical test results are borderline or unavailable. But a skilled Los Angeles DUI Attorney will challenge the admissibility and weight of these tests by:
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Cross-examining the officer’s training and ability to administer the test properly
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Highlighting the test’s low reliability rate
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Showing the subjective and ambiguous nature of “clues”
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Emphasizing that alternative explanations exist for any mistakes (e.g., nerves, fatigue, medical conditions)
How a Los Angeles DUI Attorney Can Help
As a Los Angeles DUI Attorney, I have successfully challenged DUI charges by attacking the credibility and reliability of field sobriety tests — especially the One-Leg-Stand. Many DUI arrests in Los Angeles are based on flawed or misinterpreted test results, and with strong legal advocacy, these cases can often be dismissed, reduced, or resolved more favorably.
If you’ve been arrested for DUI in Los Angeles and your case involves field sobriety tests, do not plead guilty without reviewing the evidence with a qualified attorney.
Call our Los Angeles DUI Attorney today at (818) 921-7744
Email us to schedule a consultation: andryuschenko@gmail.com
Visit our website to learn more about DUI defenses in Los Angeles
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