My Rand-McNally RVND-7725LM 'Good Sam' GPS gives me steep grade warnings - anything over 6% - but not far enough in advance to avoid such routes.
For that - after I put in the route, I have to scroll through the entire planned route in the detail mode before I start the trip.
I can select a steep grade segment to 'Avoid' - either permanently, or just for that trip.
martipr wrote:
Don't know if it is still available but the "RV Road Trip Navigator" from Trailer LIfe has an option to show grade along your planned route.
That's the main reason I keep it on my computers - as a quick check.