Quadrivial has some literal applications. It refers to a meeting point of four paths or roads, so any crossing of an intersection is a quadrivial. I did wonder if a roundabout counts as a quadrivial, for depending on the number of roads feeding into it, is a roundabout not a meeting point of four or more paths? Or is the roundabout itself considered as preventing the roads from meeting? These are the great and terrible philosophical questions of our age. I asked this question at work, and one of my colleagues met it with a firm no.
Quadrivial can have non-literal meanings too. There might be four paths to a central goal in a work or task-orientated sense. I’m struggling to think of examples, but if I wracked my brain hard enough, an answer would fall out. In the meantime, I am thinking of how to build a city on Cities: Skylines.