The police have the right to pull vehicles over if they have reasonable suspicion that a driver is committing a crime, will commit a crime or has committed a crime. During the traffic stop, the police may believe that a driver is drunk. If the police don’t have enough evidence that a driver is inebriated, then they may conduct a few tests to strengthen their beliefs (and give themselves probable cause for an arrest)>
There are two kinds of sobriety tests the police use: field sobriety tests and chemical sobriety tests. There’s a large difference between the two that you may need to be aware of. Here’s what you should know:
Field sobriety tests
The police may conduct a field sobriety test before a chemical test. A field sobriety test is a physical examination. The National Highway Traffic Safety Administration has sanctioned three kinds of standardized field sobriety tests. Here’s what they do:
- Horizontal gaze nystagmus test: evaluates eye movements for focus
- Walk-and-turn test: evaluates a driver’s ability to follow directions and stay balanced
- One-legged stand test: another balance and muscle control test
You could be asked to do a test that isn’t listed above. Other kinds of tests are considered non-standard field sobriety tests. For example, you could be asked to count in multiples of threes to prove that you’re sober.
Urine, blood and breath tests
Field sobriety tests aren’t always accurate. The police can get better readings on a driver’s sobriety levels with chemical tests.
A urine and blood test are both conducted at medical facilities or police offices. These two tests aren’t always accurate, which is why most people take breath tests. A breath test evaluates a driver’s blood alcohol content in their breath and can be done during a traffic stop with a small, handheld device.
Understand your legal rights
You should know that you have several rights during traffic stops. For example, you could refuse a field sobriety test without penalties (although the same is not true of chemical testing). It may benefit you to learn what your legal rights are and if your rights were violated during a traffic stop.
