I know I should go RTFM, but I'm traveling and don't have the ambition. Maybe someone spotted something I missed.

It appears the navigation doesn't have a detour function, at least that I could find..

 

I can answer this now. Detour is several menu levels deep, and only appears when a route is active. Not exactly user friendly, since usually when I want a detour a single button press would be a safer, less distracting way to do it. My motorcycle Garmin GPS has one..

 

I've yet to find an in-vehicle nav system that handled detours cleanly. Not saying it isn't possible.

Likewise, most systems don't do a very good job of being dynamic about re-routing. They're trying, but it's still pretty lame.

My solution for 'traffic challenged' situations is to get out the phone and use Google Maps.