It's closed to traffic, boats, and planes. I think the precaution is because of the proximity to Central Command at MacDill.
LOL! I guess that's one way to remain inconspicuous.
"Hey, Mr. Airplane Pilot Teacher. I want to learn to drive plane. I no terrorist. I don't want to learn to fly. I stay on ground! I just taxi my airplane across big bridge....."
Yeah, awful rough to try to land a plane on that bridge when there's no traffic on it...
being politically correct, they wouldn't want to be caught profiling now would they..