Can field sobriety tests prove intoxication?

If you have been pulled over by a law enforcement officer in South Carolina and subsequently been asked to do certain things like standing on one leg or walking in a straight line, you were likely the subject of a drunk driving investigation. These activities are formally called field sobriety tests and they are used before an officer arrests a person and charges them with a driving under the influence or driving while impaired offense.

Contrary to what some people might think, field sobriety tests are not used to prove that a driver is drunk. In fact, they are not even able to do that. Instead, FieldSobrietyTests.org explains that these tests are used to collect just enough evidence to show that a driver might be impaired so that the officer can legally place them under arrest. It is important for people to know that these tests are not always completely accurate.

Many factors, including a person’s mental or physical health, may contribute to the inability to pass one or more field sobriety test. Even being overweight may interfere with a person’s performance in a test. There are three tests approved for use and the accuracy rates of the tests range from 65% to 77%. Collectively, the three tests have an accuracy rate of 82%.

This information is not intended to provide legal advice but is instead meant to help residents in South Carolina better understand field sobriety tests, the reason they are administered, what they can or cannot prove, and what may factor into their inaccuracy.