Even here you get people not getting the point of blocking the bridge. They think it's an inconvenience, that the protesters are doing something bad.
That's the whole point of the protest. That's the whole point of blocking the bridge. Because anything else BLM tries to do, any other form of protest, will be ignored and people will continue on their daily lives ignoring the marginalized.
No, your hypothetical emergencies don't matter. They really, really don't in the grand scheme of things. These type of protests have been going on for over 50 years, and some people still don't get the point.