In one of our recent posts, we discussed one of three field sobriety tests that have been standardized by the National Highway Traffic Safety Administration (NHTSA). The horizontal gaze nystagmus (HGN) is the involuntary jerking of a person’s eye, and police officers use the HGN test to decide if there is probable cause to arrest a person for drunk driving.

Now let’s discuss another standardized field sobriety test: the One-Legged Stand (OLS). This test is called a “divided attention” test because it requires a driver to follow a police officer’s instructions while performing certain physical movements.

You may be arrested for DWI if a police officer thinks that you’re having difficulty simultaneously performing mental and physical exercises such as the OLS test. However, as we said before, the interpretation of a field sobriety test can be very subjective.

With the OLS test, the driver is told to stand on one foot, with the other foot about six inches suspended above the ground. The driver is then asked to count out loud: “one one-thousand, two one-thousand,” etc. The exercise will typically be timed for 30 seconds, and the officer will look for four actions that may indicate impairment:

  • Hopping
  • Swaying
  • Lowering the foot to the ground
  • Using arms for balance

According to the NHTSA, 83 percent of people who showed two or more of those indicators had a blood-alcohol content of 0.08 percent or higher.

However, what the test does not account for is the possibility of a driver having a medical condition that makes balancing difficult. Performing the OLS test on an uneven surface can also cause a person to move in a way that might suggest impairment when that isn’t the case.

We’ll discuss the third standardized field sobriety test — the Walk and Turn — in the near future.