I am thinking about getting a radio fence for our dog. She has started escaping out our front door and running away from us and it's really hard to get her back. My concern is that she is a very anxious and scared dog and I'm afraid the radio signal would terrify her. But on the other hand, we live on a busy road and she could be hit by a car if she runs out. We can't get a physical fence on our property right now. Any advice is appreciated!