Sobriety Testing in the Field: The One-Leg Stand
Summary: The one-leg stand is a sobriety test available to police. Although its reliability is not near 100 percent, police can use it to determine if more reliable yet also more intrusive testing is necessary.
Law enforcement agents employ a Standardized Field Sobriety Test, or SFST, during traffic stops in order to determine if drivers are impaired. An SFST generally comprises three components: the horizontal gaze nystagmus, the walk-and-turn and the one-leg stand. The one-leg stand, or OLS test, involves timing a subject who has one foot raised approximately 6 inches off the ground. New Jersey adheres to the SFST procedures developed by the National Highway Traffic Safety Administration, or NHTSA.
How an OLS Test Works
The purpose of OLS testing is to divide a person’s attention between physical and mental tasks, which is why an officer will ask the subject to count as well as stand on one leg. If a driver cannot count while maintaining balance, that’s treated as an indication that the person may be impaired.
OLS Testing Conditions
Police are trained to ensure that each SFST is performed in safe conditions. There are two conditions in particular that are emphasized during training and while tests are administered: surface and lighting. This test requires a level, non-slippery surface that presents no unnecessary risk should the subject fall. The driver should be able to keep his or her eyes open, and there should be enough lighting for the subject to see the officer clearly, and vice versa. If any of these conditions aren’t met, the officer should either move the subject to another location or effect change, such as shining a flashlight.
An officer conducting an OLS test will provide the driver with instructions in advance and ensure that the person comprehends them. The officer will then order the subject to:
- Stand with heels together and arms at the side
- Raise one leg about 6 inches above the ground
- Hold that position and count rapidly from 1,001 to 1,030
Subjects shouldn’t be expected to hold that position for more than 30 seconds. If the subject’s count cadence is slow, the officer should conclude the test at 30 seconds rather than waiting until 1,030.
Indications of Intoxication
The SFST training police officers receive also emphasizes identification of clues. A perfectly sober person may simply lack good balance, so stumbling, for instance, may not be enough on its own to determine intoxication. Police therefore use four clues, and if an officer identifies two or more clues, then he or she will classify the driver as impaired. The clues are:
- Swaying while balancing
- Extending arms to balance
- Putting the foot down before 30 seconds
How Reliable Is the One-Leg Stand?
Government-sponsored studies by independent groups have shown that OLS testing in ideal conditions is only about 65 percent accurate in determining if a person has a blood alcohol content, or BAC, above 0.10. These studies have also noted that not only does the test possess inherent flaws but that the inaccuracy is further exacerbated by a lack of adherence to NHTSA guidelines. Some of the issues that these studies cite and which have been used in court to defend clients include:
- Improper timing
- Officer movement
- Unsuitable footwear
- Mental impairments
- Physical impairments
- Unfair surface conditions
The Unnatural Nature of the One-Leg Stand
Some attorneys have argued successfully that OLS testing is simply unnatural for humans. People learn from childhood to use both feet in order to balance. Most people aren’t athletes with additional balance training or abilities, and thus, the argument is that the test is an unnatural demand on a person.
Contact an Attorney Today
If you’ve been charged with a DUI in New Jersey, it’s in your best interest to secure legal representation. Likewise, if you believe that officers didn’t adhere to one-leg stand testing procedures or otherwise violated your rights, you should reach out to a DUI attorney. Denis Driscoll is a DWI lawyer who provides local representation and has represented many people who have been charged with drunk driving and similar offenses. Call our law office today.