After a night out with the guys, you are heading home. You know that you’ve had a little to drink, but certainly not enough to impact your ability to drive. If you misjudged how much the alcohol has impacted your driving, you might find yourself face-to-face with a police officer.

If you are pulled over by a police officer who thinks that you could be impaired, you will likely be asked to complete a field sobriety test. These tests aren’t all the same and they can have a great impact on what the officer does when the test is completed. They are also very subjective, so remember that. Here are a few points you should know about this test:

The field sobriety test is optional

When you got your driver’s license, you agreed to the state’s implied consent law. This law doesn’t pertain to field sobriety tests. It only applies to breath and blood tests used to determine your blood-alcohol concentration.

You can decline to take a field sobriety test without having to worry about penalties. In the case of a breath or blood test, refusal comes with specific penalties. You do still have the right to refuse breath and blood tests as long as you are willing to deal with the consequences.

Not all tests are standardized versions

Not all field sobriety tests are standardized. The standardized field sobriety test consists of three parts — the one-leg stand, the horizontal gaze nystagmus, and the walk and turn. Any other tests that are requested aren’t part of the standardized test. These can include asking you to say the alphabet backwards or having you recite the alphabet starting with a specific letter.

The standardized field sobriety test has an accuracy rate of 91 to 94 percent. It is endorsed by the National Highway and Traffic Safety Administration. This is one reason why police departments turn to this test so often. They have officers who are trained specifically to do the standardized tests.

The next steps

If you don’t pass the field sobriety test, a Breathalyzer is usually the next step. This is when the implied consent laws come into the picture, so be ready to make a decision about this if it comes up.

If you don’t pass the Breathalyzer test, you will be arrested for drunk driving. At this point, your focus should be protecting your rights and preparing for your defense. This means invoking your rights when necessary and paying close attention to what is going on.