In Europe rear fog lights on cars are used in inclement weather. You see see them sometimes here but not often. Look for a tali light that is extra bright, usually the left one.
Many states advise using flashers when you are a slower vehicle (like climbing). There are advisory signs posted indicating as much.
A "disabled" vehicle is not necessarily a stopped vehicle. One can easily make an argument it is one that cannot perform normally for any number of reasons. If I am forced to climb slowly I have the flashers on.