Chatting to a knowledgeable friend about the possible role of the Ridgeway hillforts as overnight droving enclosures (they’re all about 8/9 miles apart on the western section, a good days droving by anyone standards), he first proposed that Uffington was a horse market, with the banks of the hillfort being used as display areas, then mentioned Bullstrode.
This site, he suggested, may have also served as a cattle market. *Bul*strode is situated right on the A40, a major route for many years, which if is followed to the east, crosses the first river at a town now known as Uxbridge (or “Ox-bridge”)
This doesn’t count as proof, far from it, but it’s something to consider.