Many drivers do not realize that a police officer may use a number of different methods to determine the level of impairment of a particular driver during a traffic stop. While a great deal of attention goes toward chemical testing at the scene, an officer may use several different methods to establish if a driver is impaired.
It is important to understand that an officer may issue charges even if you do not consent to chemical testing or otherwise cooperate. While you do have the right to restrict what you say or do in the interaction, you may face some form of charges no matter how you conduct yourself.
Usually, a DUI traffic stop begins when an officer believes they observe a driver behaving dangerously or driving while experiencing impairment. If you drive erratically, you may face charges whether you are impaired from substance consumption or even just a lack of sleep.
However, if you have some justification for driving in the manner that the officer noted, you may be able to get out of the encounter without any charges at all. If, for instance, you were speeding to reach a bathroom because of some stomach trouble, an officer may take mercy on your plight.
An officer may also ask you to perform a number of field sobriety tests during a traffic stop to determine if you are impaired. Be mindful of the fact that the officer is actively building a case toward your guilt throughout the interaction, and may attempt to mislead you, especially during the field sobriety test portion.
The officer may look for cues in your speech and the dilation of your pupils, as well as the way that you carry yourself in the field test. If you pass these tests, you may be able to leave the scene without charges.
Finally, you may face a chemical test. While you can refuse to take it, you may face a number of consequences if you refuse. However you choose to proceed, be sure to avoid lying to the officer, which can greatly affect the charges. Don't hesitate to obtain proper legal counsel as you build your defense against drunk driving charges.
Source: FindLaw, "DUI Traffic Stop FAQs," accessed Nov. 03, 2017