Hi there ! The roads from the 18th C that connected most major Towns in Scotland were constructed as 'toll roads' - paid for by the local 'Heritors' or landowners, jointly, who were responsible for their upkeep and repair - surface and drains etc plus bridges over streams and rivers ( though they were often erected separately by public subscription ) Contractors would be appointed to construct them, and 'roadmen' were employed to maintain them by filling up the holes etc in winter, clearing drains and shifting horse manure etc into piles in little stone 'laybys' (for stuff that was 'laid by' i.e. put aside 'til later). To use these roads, and especially to carry 'goods' over them a Toll would have to be paid - the sum depending on the goods ( coal, manure, timber etc or cattle, sheep and so on being herded ) and the wagon loads involved. These Tolls would be set (annually) - by the Heritors or the Toll keeper I can't remember. Each year at a fixed time, the Heritors would put the right to charge these Tolls up for public auction - but of course they (alone) knew what their usual outgoings were, and so would always attempt to profit from it. The Toll Keepers were usually 'experienced' Inn Keepers - who may have bid for the franchise for several Tolls in an area - and if they overbid for a Toll, and then couldn't recover the let plus their profit from the tolls, then it was their loss !. The Heritors would at the end of the Auction, have raised the funds to spend on the road's upkeep. The first edition Ordnance Survey maps ( of the 1850s) show the position of these Toll points - often chains over the road, and a wee house for the Toll Keeper or his employee to watch out and operate the chain or barrier. As I remember, both the Toll houses you mention are still there - though now converted and extended in at least one case (Carmichael, on the edge of Thankerton Moor) The Avon Bridge one is a ruined shell. You can view these on the First Edition OS maps on the National Library of Scotland website, in the maps collection and use Google Maps to see them as they are today ... GGR