Roads in Northern Kentucky were initially created by herds of Buffalo. Dixie Highway is where the Buffalo went, and Daniel Boone, Simon Kenton and other unnamed early explorers used these roads. When settlement came, it was common for individuals to maintain the roads in condition good enough for buggies and wagons. This is how they made a living, and they charged for passage on the roads. For some, in high traffic areas, it could be very lucrative.
Florence had at least four tollgates: one the road going to Burlington, another on the road to Union, and yet another south of Florence on Dixie Highway. There was a tollgate in Erlanger, which moved to the Boone Kenton line on 7-1-13. My guess is that this is the tollgate Lloyd took pictures of, because it would been on his beloved "Stringtown Pike." But that's a guess. Many of Lloyd's pictures have notations on the back; these do not.
Boone County "freed" the roads by buying them from their owners. Dixie Highway north of Florence was freed on 8-14-16 along with the once south of Florence, and a third tollgate just north of Walton (near the Gaines house). The Burlington Pike was freed on 9-17-15 and the Union Pike freed on 8-1-16.