When Do You Need To Bug Out?

At what point do you bug out? What is the single event that makes you jump up and run? I think I will shelter in place until I have to bug out but I think this is the plan for a lot of people, but I don't want to wait to long and have a problem getting out of dodge. I think I live in a nice size town and we are about 35 miles from Sacramento and less to the open woods and some nice area to bug out to, but this is what every other person here will be thinking so I have two real nice out of the way BOL to go to and both are very close to me and I know that not very many people know about the two areas. Me and the wife have been there very many times and have set out a few caches with needed items in them. But what will be you line in the sand? What will get you to bug out and hit the road? As for me when the collapse hits I will start the bug out and be ready in about one or two hours. I have a truck and small trailer and can load them both in a very short time. With me the wife and three kids we can take a few routes I have planed out. I would scout out ahead of the group and make sure we could go on. I know that no plan is 100% but I have worked out my plan and think it will work. I hope we can get the RV soon and get out on the road full time. I just don't see us having much time till the collapse so I am working on the back up to the back up plan. Keep up your prepping and stay on the task of survival, because your life will depend on it one day soon. Life goes on........will you?