Can roads only exist if a violent entity forces us to pay for them?
Traffic laws are unnecessary. People don't follow the rules of the road primarily because they're afraid of getting fined or arrested. People drive safely because of our instinct for self-preservation. We don't want to die. We also (generally) don't want to kill other people.
General guidelines of conduct are useful so that people know how to behave safely on roads. But we don't need to be violently forced into obeying those guidelines.
RE: Questions for Anarchists: What if I Have More Guns than You and I Take You Property by Force?