This is a grey area, look at some countries where you’ve had protesters block aid trucks to refugee camps saying that their national is imminent danger from these people. I think a key here is the degree and length of traffic blockage. When it is being used to essentially lay siege to a place it is ambiguous whether it’s violent or non violent. Temporary limited disruption of traffic is probably pretty firmly in the non violent column
All of the first amendment rights have gray areas. All possible sets of rights probably have the same issue, no matter what consistent moral framework you choose.
