On August 28th in 1773, Sam Johnson and James Boswell start their day in Calder, reaching Inverness by nightfall. They began their Highlands tour on the 18th of August, so were 10 days in at that point.
Scott too toured the Highlands, and he describes, in his "The Highlands and Western Isles of Scootland", meeting a local, and perceiving how unpopular English roads were. According to Scott, the roads were viewed as a form of tyranny. Many still walked, or rode horseback, on the old country tracks, rather than use the newer roads; especially to avoid the "turnimspike".