The rail line you are talking about is a Class 1 owned by SOO and they aren't likely to give up ownership of it. I think there was some talk about "renting" time on it but that was denied.

Also, that line doesn't terminate at Wal-Mart South, it's terminates a little bit north of there (1/4 -1/2 mile?). Also, sure, that line is pretty empty and there is a the old Libbys land that the tracks go past but I'd prefer that land to not be used for parking, tbh. Maybe it would work but probably not. There is the old Kmart builiding that the track goes past and Mayo is currently renting the parking lot around the old KMart building. Maybe build a large ramp instead of a parking lot at KMart building? Prioritize and optimize traffic from 52 and 63 to go to the KMart building? I dunno. Mayo doesn't like to build parking ramps they can't charge people to use.