Four Things You Didn't Know About Field Sobriety Tests

You Don’t Have to Take Them

You’ve probably heard of the “implied consent” law which states you agree to consent to a BAC test, however what most people don’t realize is this law doesn’t apply before you’re arrested. Field sobriety tests are entirely optional, and you may decline to participate in them. However, just because you decline doesn’t mean officers can’t establish probable cause and won’t choose to arrest you anyway.

An Officer Doesn’t Have to Offer one To You

Were you stopped by an officer and arrested straight away without so much as them even asking you to track their finger? In some cases, officers don’t even really need to take extra steps to establish probable cause. If you present enough evidence that you are driving drunk before they even ask you to partake in a sobriety test, they can arrest you on the spot.

There are Only Three Approved Field Sobriety Tests

People have heard stories of officers asking intoxicated individuals to do all sorts of things, however there are only three approved field sobriety tests: the walk-and-turn test, the one-leg stand test, and the horizontal gaze nystagmus test. Any other field sobriety tests that may have led to your arrests are likely riddled with errors that could lead to a false conclusion and therefore an unlawful arrest.

Field Sobriety Tests are Wildly Inaccurate

Similar to the previous point, even though these tests have been standardized, they are still prone to confirmation bias and other forms of human error that can lead to unreliable results. A NHTSA and Southern California Research Institute study found that the horizontal gaze nystagmus test, the most accurate of the three approved tests, was only successful 77% of the time—that’s an error in just over one out of every five tests! When multiple tests are used, their accuracy increases, but so does the possibility of human error discrediting test results.