The 'Roman Bridge' was probably built in the mid 1700s.
There is a report where the author says his father remembers it being built.
Also there was a great flood in 1740 (I think) that destroyed many of the bridges and this may have included teh 'Roman Bridge', which would then have been rebuilt around the mid 1700s.
It was given the name 'Roman' to encourage tourists from Manchester who came for day trips to 'The Roman lakes'
There is a theory that when Samuel Oldknow built his Bottoms Mill he also planned on having the new turnpike running past it. But this would have meant it would aslo run past Mellor Lodge. When the turnpike was constructed it was higher up the valley and is now called Strines Road so I do not think it was ever used as a toll house.