A Portable Breath Test (PBT) is a small, handheld device used by police officers to test a driver's breath for the presence of alcohol. This test is usually conducted on the side of the road during a traffic stop. The PBT is a preliminary test that is often used to determine whether a driver should be arrested for DUI. The results of the PBT cannot be used as evidence in court in New Jersey, but they may be used by law enforcement officers to guide their decision-making when deciding whether to arrest a driver for DUI.