Update: this work is not related to the Gila River Bridge project. Apologies for any confusion.
ADOT is advising drivers that there will be a temporary lane shift on SR 79 in Florence on Monday 12/5 from 7:00 a.m. to 5:00 p.m., and again on Tuesday 12/6 from 7 a.m. to 5 p.m. Southbound traffic will be diverted to the middle lane near Virginia Street, around milepost 133.
Original source can be found here.