Final answer:
If you notice someone driving erratically behind you, the best course of action is to let them pass and maintain a safe distance. Avoid close interaction or monitoring that could alter their behavior unpredictably. Always prioritize safety and seek assistance when needed.
Step-by-step explanation:
If you notice someone driving erratically behind you, you should let him or her pass you and position your vehicle with plenty of space behind the bad driver. This ensures your safety and reduces any potential distractions or obstacles for the erratic driver. It is critical for your safety to avoid engaging or interacting with an impaired or aggressive driver, as well as to be as inconspicuous as possible; the presence of another vehicle closely observing them might influence their behavior in an unpredictable way.
Much like the observer effect where people act differently when they know they are being observed, as with the example of changing driving behavior when a police car is behind you, it is best to act unobtrusively and give the erratic driver space. Additionally, if you are witness to a scenario where someone is in need of help, as suggested in the bystander effect, it is important to be proactive in ensuring assistance is given, either by helping directly or by contacting someone who can, like an authority figure.