It would be awesome if the the entire bridge could slowly move as one while traffic keeps flowing over it. That would require far more and far bulkier wheels than the current ones designed to carry only one support segment. That will have to remain the stuff of fantasies...
The bridge could temporarily lift just the 2 ends and traffic could continue slowly under the bridge while the bridge moves ahead. However, it needs to also raise its height for trucks to pass under or alternatively, trucks could be temporarily suspended/rerouted from the road while the bridge moves.
Sure, but that can happen at night with minimal disruption to traffic as it takes only the time to move it, not the time to disassemble, move, and re-assemble.