Humans have a right to assembly. I don't believe vehicles do. Unless there's something in the Canadian constitution that contradicts this...
That said, I have no problem with the protest as such. They just seemed to not understand that it made no one sympathetic to their so-called cause. Civil disobedience is just fine with me. I come from a country that wouldn't be free without mass civil disobedience. There was a much larger protest involving many more trucks blocking the road in Delhi, over much more concrete stakes that actually succeeded. I was cheering them on, because using trucks to stop traffic is a totally fine way to disrupt regular functioning of society and make it pay attention.
But if you choose a stupid cause to promote with such a protest, far from gaining wider sympathy, you'll just have the rest of society even more firmly entrenched against your position. That was the issue with the Candian truckers. I have less issue with the means than I do with their goals.