After a few drinks with your friends, you hop in your car. A few miles down the road, you catch a glimpse of red and blue in your rearview mirror. Your breath catches as you pull over.

Many people have experienced this moment. They thought they were okay to drive, but then they get pulled over and are asked to complete a field sobriety test.

What happens during a Field Sobriety Test?

Once a police officer suspects someone may be driving under the influence, the officer will ask the driver to perform a series of tasks. These tasks will allow the officer to determine if the driver is under the influence.

  • The walk-and-turn test: This test is used to gauge the balance and memory of the person in question. The officer will ask the driver to take nine steps in a straight line and encourage them to keep count on their own. Before the driver starts this walk, they have been instructed to turn on the ninth step. This turn must be completed by using only one foot. If the driver is unable to keep track of their steps and cannot keep their balance, the officer may further suspect that the driver is intoxicated.
  • The Horizontal Gaze Nystagmus test: Although the name of this test is intimidating, it measures the eyes of the person in suspicion. An officer will hold a flashlight or pen up to the driver’s eyes and request that they follow the object with their eyes only. This will allow the officer the chance to properly observe the eyes. Someone who has been impaired by alcohol will have a difficult time tracking the object. In addition, their eyes may have an involuntary jerk. This jerk is common in people who are impaired and is a tall tell sign to officers.
  • The one-leg stand test: During this test, the driver is asked to stand on one foot for 30 seconds. This test helps determine their balance once again. The driver is not allowed to hop, sway, return to a standing position or use their arms to steady themselves. This test gives the officer a better idea of how unsteady the driver is.

The Field Sobriety Test aims to make the road a safer place. All the tests have upsides and downsides. They are not a perfect system. With the help of all three of the tests together, the officer can hopefully determine whether the driver should be behind the wheel or not.