Basically you run backwards on a road with very light traffic. Run until you see a car coming your direction, then turn around and run forward until it passes. And repeat for as long as you wish!
The background photo in the graphic above was actually from a run last Sunday, when my sis was with me on a bikeride on a logging road with no traffic, but you can really play this game anywhere, switching between song chorus and refrain or just picking a tree or flower or telephone pole.
Just as long as the road is flat and straight and doesn’t get a ton of traffic :).
This post may be sort of a “duh” but I felt clever in the moment and had fun, so there’s that.