Like all Field Sobriety Tests (FSTs), this test is voluntary, and you do not have to submit to it.  Additionally, even if you do and the results indicate a presence of alcohol on your breath, there are many alternative explanations for these results that can create a reasonable doubt that the driver was actually under the influence of alcohol.

Many people think that the PBT is same as the “Breathalyzer,” and while it is similar in idea and form, it is much different.  While the Breathalyzer may be administered roadside, it is most often administered after arrest at the police station.  The PBT, however, is administered roadside, and is used to determine whether or not there is a presence of alcohol in a driver’s breath.

The PBT is often called an alco-sensor, and is used to determine probable cause for arrest for DUI.  The Breathalyzer, however, is used to determine one’s Blood Alcohol Content (BAC).  Though the PBT indicates an estimated BAC, this value is not admissible in court.  The PBT is only admissible to show the presence, or non-presence, of alcohol in one’s breath.

REMEMBER: The PBT is notoriously unreliable, as many factors can cause it to incorrectly indicate positively for alcohol — including acid reflux, and certain tobacco, mouthwash, or mints.    Mere indication of the presence of alcohol on one’s breath, without more, is insufficient to establish that one was driving under the influence (DUI) beyond a reasonable doubt.