I mean, any protest that isn’t disruptive or making people uncomfortable isn’t effective. That being said, there were some BLM protesters who chained themselves to some cement filled barrels a few years ago. They completely blocked a highway, causing delays for several ambulances that had to be rerouted. That’s just stupid and dangerous. But if your goal is to force politicians to acknowledge the issue and take an official position on it, blocking a street or disrupting a public event is an effective tactic, as long as it’s done safely.