What is a field sobriety test?

Being stopped for suspected drunk driving is intimidating. But you’re your interactions with police and their gathering of evidence impacts your DUI defense. The field sobriety test is one method for obtaining evidence.

Police administer the field sobriety test when a motorist is suspected of driving under the influence of alcohol or drugs. Three standardized tests are used.

The horizontal gaze nystagmus test involves tracking eye movement. A police officer moves their hands side-to-side and requests the motorist to follow their fingers or a small flashlight or pen. The driver may fail if their side-to-side gaze cannot smoothly follow the moving object, their side-to-side gaze is jerky, or this jerking starts before the eye is 45 degrees of center.

Next, the walk-and-turn test is used when police ask the driver to take 9 heel-to-toe steps by touching their toe with the heel of their foot moving forward. They then turn on one foot and come back the same way. The driver fails if they are unable to keep balance when receiving instructions, start before instructions are completed, do not touch heel-to-toe, use arms for balance, step off a straight line, take the wrong number of steps or make the wrong turn.

The one-leg stand test requires the driver to stand with one foot approximately half a foot off the ground and count numbers beginning with 1,000 for 30 seconds. Signs of impairment include swaying, using arms to balance, hopping and putting the wrong foot down.

These tests have flaws. The driver may be using medication, have physical disabilities or may be nervous or tired. Also, police may not administer or judge the results properly, objective or consistently or give clear instructions. Even small amounts of alcohol, more than one alcoholic beverage per hour, can impact performance.

A motorist can refuse these tests despite what a police officer may say but they may have to undergo a breathalyzer test. Police have used this refusal as grounds to suspect that the motorist is hiding something and arrest them. A driver who passes the field sobriety test or a breathalyzer test may be arrested if the police believe that they are a danger to others.

Even if you refuse this test, you should be respectful and not aggravate this situation. An attorney can object to improper procedures and protect your rights.