Nice series, Eric. Glad you got out!
#10 is the clear winner (Mt. Pleasant Bridge), mainly because of the little hint of fading sunlight along the inside, and the (uncluttered) composition. A little post-processing to bring out the colors or emphasize the wood would be great.
As far as the haze, there isn't much you can do with filters for that (even "haze" filters) but you seem to be pretty close to your subjects, so it really is only a background issue and might even help. Overcast is okay lighting as well, if you pump up the reds later on.
And I know it's not always there, but having a good foreground (even OOF) element like some leaves framing the shot or a sign for the bridge, or even a stretch of road from a very low (hunched over?) perspective can emphasize these structures. Choice of lens can help too (wide?)
That said, I've never shot covered bridges, and I'm kinda jealous as you seem to have a plethora of subjects!
-Mark