Please share with us how to safely close a road in a hurricane. Sure, physically the road can be blocked with concrete barriers or dump trucks, but you can't put up any warning signs or devices.
Dump trucks are often equipped with a yellow rotating strobe on the roof of the cab.
There's the warning device.
Hopefully, someone is thinking ahead of time and will close before the hurricane actually hits the bridge. With that being said, you can always close it at the approaches leading up to the bridge. With an interstate, you close it at the prior interchange. I would have thought that would have happened here, but apparently not. And you can put up warning signs, using the portable signs cops carry with them, using flares, using patrol cars with lights ablazing to warn people not to go any further. You do not do this on the bridge itself, but on the approaches to the bridge.