This has to be a joke. Just read the last paragraph of the article below:
Still, summer will be different on the Cabot Trail without the thunder of motorcycles rolling through the hills. Some Nova Scotia motorcycle clubs have talked about “rolling protests,” riding motorcycles through the Trail at slow speed to show their unhappiness with the policy. However, those plans were abandoned when some members pointed out that wouldn’t be any different from their normal riding style.
It is not the speed, it is the slow moving two cylinder bikes with loud pipes. The ones that may even rent a bike and who forgot about learning to ride a bike before started riding these trails. The ones you see at Daytona and Sturgis.
Of course it's an April Fools joke. However, you'd hear no complaining from me if they banned loud pipes. I have sympathy for the folks who live along side the Blue Ridge Pkwy. and what they have to endure all riding season.