Field sobriety testing

Field sobriety testing is a series of physical and cognitive tests used by law enforcement officers to determine if a person is impaired by alcohol or other drugs. These tests are typically administered roadside and can include a range of exercises such as standing on one leg, walking a straight line, and following a moving object with the eyes.

History

Field sobriety tests were first developed in the 1970s by the National Highway Traffic Safety Administration (NHTSA) in the United States. The NHTSA conducted research to develop a standardized method for law enforcement officers to assess impairment. The result was the Standardized Field Sobriety Test (SFST), which is still in use today.

Standardized Field Sobriety Test

The Standardized Field Sobriety Test (SFST) is a battery of three tests administered and evaluated in a standardized manner to obtain validated indicators of impairment. These tests include the Horizontal Gaze Nystagmus (HGN), the Walk-and-Turn, and the One-Leg Stand tests.

Horizontal Gaze Nystagmus

The Horizontal Gaze Nystagmus (HGN) test is based on the involuntary jerking of the eyes as they gaze to the side. In this test, the officer will observe the eyes of a suspect as the suspect follows a slowly moving object such as a pen or small flashlight, horizontally with his or her eyes.

Walk-and-Turn

The Walk-and-Turn test is a "divided attention" test. It requires the suspect to listen to and follow instructions while performing physical movements. In this test, the suspect is directed to take nine steps, heel-to-toe, along a straight line.

One-Leg Stand

The One-Leg Stand test is also a "divided attention" test. It requires the suspect to stand with one foot approximately six inches off the ground and count aloud by thousands (One thousand-one, one thousand-two, etc.) until told to put the foot down.

Non-Standardized Tests

In addition to the SFST, there are non-standardized field sobriety tests that are often administered by law enforcement officers. These can include the Finger-to-Nose test, the Alphabet test, and the Finger Count test.

Criticism and Controversy

Field sobriety tests have been criticized for their lack of reliability and validity in determining impairment. Critics argue that these tests may not be sensitive to impairment caused by drugs other than alcohol, and that they may be influenced by factors such as fatigue, nervousness, or certain medical conditions.

See Also

• Drunk driving in the United States
• Breathalyzer
• Blood alcohol content

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