If you’ve been pulled over on suspicion of drunk driving in Washington, the officer will likely ask you to perform a series of physical tests on the roadside. These are called field sobriety tests, and understanding how they work can make a difference in your defense.
What Are Standardized Field Sobriety Tests?
The National Highway Traffic Safety Administration (NHTSA) has validated three tests that officers use to determine if a driver is impaired. These are:
- Horizontal Gaze Nystagmus (HGN)
- Walk-and-Turn
- One-Leg Stand
When administered correctly, these tests are supposed to help officers decide whether to arrest someone for DUI. But the key phrase here is “administered correctly.” Many factors can affect the results, and not all of them have anything to do with alcohol. If you failed one or more field sobriety tests, that doesn’t mean your case is hopeless. Eastside DUI attorneys regularly examine the circumstances surrounding these tests. Was the officer properly trained? Were the instructions clear? Was the testing location suitable? These questions matter.
The Horizontal Gaze Nystagmus Test
The HGN test involves an officer holding a pen or small flashlight about 12-15 inches from your face. You’re asked to follow the object with your eyes as the officer moves it slowly from side to side. What the officer is looking for is an involuntary jerking of your eyes, called nystagmus. While alcohol can cause this jerking motion, so can many other things. Certain medications, fatigue, neurological conditions, and even the flashing lights from a police car can trigger nystagmus. The test also depends heavily on the officer’s training and ability to spot the signs correctly.
Walk-and-Turn Test
This is exactly what it sounds like. The officer will ask you to walk heel-to-toe along a straight line for nine steps, turn around, and walk back the same way. You’ll need to count your steps out loud and keep your arms at your sides. Officers watch for eight specific indicators of impairment, including starting before instructions are finished, stepping off the line, using arms for balance, or taking the wrong number of steps. The problem is that this test requires good balance and coordination to begin with. If you’re tired, nervous, wearing uncomfortable shoes, or standing on an uneven roadside, you might struggle even if you haven’t had a drop of alcohol.
One-Leg Stand Test
For this test, you stand with one foot about six inches off the ground and count aloud by thousands (one thousand-one, one thousand-two, and so on) for 30 seconds. The officer looks for four signs of impairment: swaying, using arms for balance, hopping, or putting your foot down. Like the Walk-and-Turn test, this one assumes you have good balance under normal conditions. Age, weight, physical fitness, injuries, and even anxiety can all affect your performance. Standing on the side of a busy road with cars whizzing by isn’t exactly a calm testing environment.
Why Testing Conditions Matter
A Bellevue drunk driving defense lawyer knows that field sobriety tests are far from perfect. Weather conditions, poor lighting, uneven surfaces, and officer error can all skew results. The tests are also voluntary in Washington, though officers don’t always make that clear. According to NHTSA research, even when performed under ideal conditions, the three-test battery is only about 91% accurate at detecting a blood alcohol concentration of 0.08% or higher. That leaves room for false positives, which is why challenging these test results is a common defense strategy.
What This Means For Your Case
The results of field sobriety tests are often the foundation of a DUI arrest, but they’re not the final word. A Bellevue drunk driving defense lawyer can review the details of your stop, identify problems with how the tests were conducted, and build a defense based on the specific facts of your case. Understanding what these tests measure and what they don’t is the first step in protecting your rights.
