I know the fear of seeing a car come towards you like this, but not of actually being injured from it. It is certainly traumatic. I'm unsure of why you seem to be the main person dealing with this, but suggest that you find others -- family, her friends, her MD, social services or whatever to also assist in giving her the same message, that telling you to "GO AWAY" isn't the right choice.

Be sure to put up good boundaries between her reactions and choices, and what you wish she would do. Good wishes.