Its first section opened in 1973, and the rest was all built, but the A41(M) doesn't exist. It was canned in favour of orbital roadbuilding, and later resurrected in a more modest form.
It crosses cattle grids and untamed moorland, it climbs 1-in-4 hills and plummets through hairpin bends, it runs single-track through woodland and historic villages. It's rugged and beautiful. Is it really the A39?