I grasp the reasoning, but I also recognize that there is no good alternative to that road when it comes to certain hauls. The same geography that makes the route "fun" for riders is also the reason there are no good alternatives routes within a reasonable driving distance for local deliveries.
I also question the severity of danger posed by the few rigs that go through in a week. Even the youtube "proof" video from us129 called Chaos on the Tail of the Dragon or something like that shows a rather tame drive down the road by an obviously skilled driver successfully maneuvering his rig down a tight road with no real drama to speak of. A few tight crawl-by situations, yes, but nothing life-threatening.
I don't think a total ban is realistic given the geography and available alternate haul routes, especially when it comes to serving local communities and businesses. Perhaps an escort requirement would be a more reasonable compromise that would discourage long-haul cut-through traffic but preserves a reasonable short haul delivery route to communities and business in the immediate area.
Yes, an escort requirement would still mean that you might get stuck waiting while a rig negotiates some of the tighter corners and hairpins, but it would provide a suitable response to any "safety" issue posed by the rigs and other traffic.
Also, in addition to the signs at each end advising trucks that the route is a tough one to drive, post signs for OTHER traffic throughout the route at key points reminding them to take care on blind corners because of the chance of obstruction around the bend, whether by rig or by SUV with a big *** house or boat trailer.