Can winter weather and other factors influence field sobriety test results?

Law enforcement strives to keep North Carolina roads safe by taking impaired driving seriously. A conviction for DWI can lead to a host of devastating penalties including jail time, fines, loss of driving privileges and installation of an ignition interlock device. Unfortunately, many cases begin with nothing more than observations and a subjective measure of impairment.

While snow is an uncommon occurrence in most parts of North Carolina, the winter months often bring heavy rain, strong winds and less daylight. Certain factors can negatively impact a driver’s performance in the three standard field sobriety tests:

• Horizontal gaze nystagmus: In this test, the officer instructions the driver to follow an object, often the tip of a pen, moving only their eyes. The officer will watch for involuntary jerking of the eyeballs. This test can be impacted by the use of contact lenses, a medical condition, strong winds or blowing particulate matter in the air.
• Walk-and-turn: The officer will instruct the driver to take nine heel-toe steps in a straight line, turn, and walk back along the same path. This test can be impacted by heavy wind, slick pavement or heavy clothing worn to combat the cold weather.
• One-leg stand: The officer will instruct the driver to stand motionless, raise one foot six inches above the ground for 30 seconds. This test can be influenced by heavy rain, strong wind or uneven pavement.

Even though law enforcement officers receive special training and instructions regarding administering field sobriety tests, their results are still largely subjective. This means that several factors – both biological and environmental – can negatively impact a driver’s ability to perform the test’s objectives in a sufficient manner. Unfortunately, the officer might read this performance as indicating the lack of physical or mental acuity necessary to safely operate the motor vehicle.

If you were arrested or charged with a crime, it is crucial that you act quickly to protect your rights and freedoms.