Do you use Google Maps to examine the details of the proposed route? This may be easier to do from a computer than a phone.
One step is to just zoom in enough to see all curves. Terrain view and sat view also give useful information. And then there's streetview.
Use those tools at home to review the area you just drove. You might even be able to see the inside of that covered bridge! And if there isn't a streetview, it's a good indication that the route is too minor to drive with a big RV.