This seems the most pointless cottage industry running the machines to move the barriers twice a day and back. I suspect $M's and perhaps up to 50 staff at a guess...
Why? The bridge is fed by a max of 4 lanes both North and South, they act as choke points so having 5 lanes in the priority direction on the bridge itself is of no benefit.
Meanwhile on the low priority direction, the huge amount of lane-changing caused by the 3 lane constriction (plus the lanes don't line up, they are up to 2 lanes out of alignment), and consequent capacity change over the bridge does cause its own additional level of congestion and traffic delay.