The installation will bring the tower to 480 feet and 91 percent completion. Another section will be added later - that will bring the tower to 525 feet.
Caltrans and the CHP are concerned all of the activity will become a distraction to drivers and are urging people to be cautious.
"We just want to encourage drivers to keep their eyes on the road and to maintain a safe space cushion between the vehicles in front of them and try to avoid the distraction of the construction that is taking place on the north side of the bridge as they complete the tower," said CHP Ofc. J.T. Taylor.
The Bay Bridge will soon be world's largest self anchored suspension bridge. The new bridge is expected to be completed by 2013.
