I just moved out of living in Mobile for 2 years, just 3 weeks ago. I used to travel I-65 boring 4-hr trip through Flomaton area every other weekend to get to my golf course home, then full of scale model HO trains near Calera, Al.. Unfortunately, not being from Alabama (originally from upstate NY), I've been chased away from most railfan or historical railbed hunting activities either by shotgun or sheriff. I still try when the mood is right, but most of the dozen or more times traveling through Flomaton, I was short on time (ie; needed to get to my house ASAP in 3 hours or less on a 4 hour drive, then pack and load my truck for return to Mobile in less then 10 hours).
I only ventured off the interstate there about 6 miles once for gas and a restroom. If I had better reason than my own curiosity, such as your inquiry, I would have made the effort to leave an hour sooner so I could spend the time checking into it.