According to the Port Royal web site.
Port Royal River Bridge Closing:
The detour for the Port Royal River Bridge will begin on Friday, June 26, 2009 and run through August 26, 2009. At this time, the bridge will be closed completely.
After August 26, a light will be set up to allow traffic to cross the bridge one lane at a time.
Not sure about detour instructions, we'll post any updates here. Please allow extra time.