Unless you are stopped at a DUI checkpoint or you are involved in an accident, a DUI investigation will usually involve you being pulled over for erratic driving or a traffic violation. When the officer stops your vehicle, he or she typically will not have enough evidence for a DUI arrest. The officer will likely ask you a number of questions about where you are coming from and whether you have been drinking. While you should not lie to the officer, you should not answer these questions unless you have ingested absolutely no drugs or alcohol. While you should have your license and registration ready to provide to the officer, you are not required to answer questions about your activities.