This technically acts contra to Roads (Scotland) Act as the roads authority has a statutory duty to provide a general purpose road for the use of all traffic, in the way it should expect to use that road - and thus a route over which you can cycle should be provided. This stupid arrangement makes no allowance for those who are riding cycles because they cannot walk as well as they can ride - I know of one monoped who would have immense difficulty if he was touring without his prosthesis, and forced to walk and push a bike (basically he couldn't).