Answer: Get an Injunction against his activity
Step-by-step explanation:
An Injunction is a warning or order from a Court of law that prohibits a person from initiating, engaging or continuing to engage in an action that is going against the legal right of another person.
As this driver is infringing on your rights to not be intimidated by another, you can get an injunction from the Courts to compel him to stop his actions of following you around and threatening you.