Drivers stopped by police and suspected of driving drunk will typically be asked to complete a few roadside tests, called field sobriety tests. Police administer these tests to determine if a person is impaired.
Considering how often police use these tests and the significant impact they can have on whether a person is ultimately arrested for drunk driving, it could be easy to assume they are accurate. However, the fact is that these tests are not perfect.
How accurate are they?
Field sobriety tests consist of three components: the walk-and-turn test, the horizontal gaze nystagmus test and the one-leg stand test. These tests attempt to measure things like a person’s balance, vision and ability to divide attention. Alcohol can adversely affect these functions, but performing poorly in these tests does not mean a person is impaired.
According to data analyzed by the National Highway Traffic Safety Administration, each test by itself is between 65 and 77 percent accurate. In other words, there is a lot of room for inaccuracy.
Factors that affect accuracy
Numerous conditions can affect the accuracy of field sobriety tests. Some common factors include:
- Poor lighting
- Uneven surfaces or poor footwear
- Officer bias
- Unclear instructions by police
- Medical conditions
- Language barriers
- An especially distracting environment
These factors have nothing to do with whether a person is intoxicated, but they could result in inaccurate conclusions.
Challenging field sobriety tests
These tests have serious limitations, and they are far from perfect. As such, it can be crucial to examine the administration of field sobriety tests and a person’s performance if he or she winds up facing drunk driving charges in Tennessee.
It is important to remember that you have rights and legal options, even when police tell you you’re guilty or claim that you have failed a test. Such options include the right to challenge the charges against you and defend yourself, which is crucial in protecting your freedom and your future.