A police officer must have probable cause before arresting someone for drunk driving. Besides being pulled over for erratic driving, a police officer might notice a drunk driver in any of the following situations: after the driver was involved in a car accident, after the driver was pulled over for another traffic violation (such as running a red light), or after the driver was stopped at a sobriety checkpoint.

After being pulled over, the police will further investigate the possibility of drunk driving. They will observe the driver's behavior, looking for tell-tale signs of intoxication, such as slurred speech. They will also perform a variety of field sobriety tests, ask questions, and may even give the driver a preliminary breath test (PBT). The driver is not required by law to take these tests or answer these questions, but this refusal may only serve to incriminate him further.

Sufficient probable cause, will lead to a drunk driving arrest. On the way to the police station, the officer should read the suspect his Miranda rights and notify him of his legal obligation to take a chemical test.

After a drunk driving arrest, if there is sufficient evidence and a BAC of .08 or more, a person will most likely have his license suspended for a substantial amount of time. The suspect will also be kept in a holding cell until his intoxication wears off. He will then be given a date to appear in court for his arraignment. If you are arrested for drunk driving, it is advised that you seek legal counsel as soon as possible.