Part of the problem is, of course, defining "RV Friendly"
You can set you gas station filter on trip wizard to include dump station and Propane.
Though I've not found that to be terribly useful in New England.
The Fuel stops on the Mass Pike were usable by RV, but not entirely convenient. If you're using Diesel, you can get to the truck pump after parking at the plaza, but if you're using Gasoline, you're stuck with going to the fuel pumps and then leaving.
Gas Buddy finds less than a dozen RV Friendly stations in NE.
I found few in Maine that I could get my rig with Toad into and out of if traffic cooperated.
Fortunately, New England is small enough that you only need a couple of places.
RV Trip Wizard seems to concentrate on the main highways. Not necessarily useful.