I'm not 100% clear on how this works, but I'll give it a stab..

So it does NOT pop up and tell you there's traffic. The icon just turns RED. If there is a WRECK - and not just slow traffic, lane closure, etc. - and you have Dynamic Routing turned on, it will reroute. Sometimes.

I came across a set of selections ON the "traffic screen" the other day that I hadn't seen before and one of them was to route around it. I don't remember seeing these selections before, and wondering how in the devil do I make it reroute.

It seems inconsistent, illogical or maybe I don't get it. It has rerouted before, but it seems to like to tell me "xx miles left to detour" without actually detouring. Kind of frustrating.