If a person is driving and hears a police siren behind them, they should pull over to the right side of the road and stop the vehicle as soon as it is safe to do so. They should remain calm and wait for the police officer to approach them. It is important to follow the officer's instructions and be respectful. If the person is unsure why they were pulled over, they can ask the officer for clarification. It is important to remember that the police officer is there to ensure everyone's safety, and cooperation can help resolve the situation quickly and smoothly.