Field sobriety tests may be the main way that police determine if you are intoxicated behind the wheel, but that does not mean they're reliable or accurate.
The tests catch a lot of flak, despite their widespread use. Some say they're too subjective, simply letting an officer decide if you're impaired based on what he or she thinks, regardless of the facts. Others say that they are not even really necessary with the availability of breath tests. Still others point out that road hazards -- loose gravel on the side of the road or a slick surface after a heavy rain -- can make you fail them no matter what you have had to drink.
Sober drivers fail, too
Part of the problem is that sober drivers may struggle to pass these tests. You could be someone who has never had an alcoholic drink in your entire life. You could still fail the test after getting pulled over because you swerved out of your lane while changing the radio station. Then you could get arrested because the officer thinks you are intoxicated. Yes, you will eventually be able to take a breath test or a blood test to show that you're sober, but you still have to suffer through the inconvenience of an arrest.
Medical conditions and injuries
One reason drivers fail is because of preexisting injuries or even disabilities.
For instance, perhaps you seriously injured your back at work. You can't stand up straight to walk, and you just shuffle along. You take painkillers every day -- the type that you can take and still safely drive -- and you go to rehab, but you know you have a long road ahead of you.
Driving may be safe, but can you effectively do the walk and turn test? If you shuffle along and stumble while you turn, the officer is probably going to think you're drunk. In actuality, your back pain just flared up and you tried to gut it out.
Others have permanent disabilities. Maybe you injured your right leg 20 years ago, and it's never been the same. You can barely balance or support yourself on that leg alone. It does not impact your driving, but are you going to fail the one-leg-stand test if the officer does not want to hear your excuses and insists that you stand for an extended period on that right leg?
Even the nystagmus test, which examines eye movement, isn't a perfect science. Excessive alcohol consumption can make you fail, but so can a variety of other issues, from eye disease to B-12 deficiencies to traumatic head injuries.
Your rights after a failed test
Even though their accuracy is disputable, field sobriety tests continue to see everyday use. If you fail, make sure you know your rights.