Pay attention to the signage on roadside :B
We used secondary/back roads during our 7 yrs FT travel.
Missed one sign due to trees/bushes over grown but it was obvious that the bridge was very low.
Like you we just turned around
One other overpass snuck up on us due to road going over the overpass then making a turn and merging with road going under overpass.
Back up or go under :S
10 vehicles backup behind us.....one guy yelled "you'll make it. They cut the road surface down and never changed sign"
We crept under at idle.....just cleared.
GPS made too many errors to be reliable enough for back road travels. 'Miss Garmin' got muffled and out in a bag