only collected in the westbound direction.) The low bid by a joint venture of American Bridge and Fluor Corp., named 'American Bridge-Fluor, was accepted on April 19, 2006. Design and construction Skyway Viaduct The skyway viaduct connects the SAS portion of the bridge with the Oakland shore. By 2007, 75 percent of the skyway portion was completed. Since this section crosses the shallower portion of the bay, the foundations were constructed within sheet-pile cofferdams. By mid-2009, the final connection of the viaduct portion with ground level at the eastern end was being finished and the pedestrian walkway was being attached to the completed sections. Rather than set pilings deep enough to reach bedrock, the pilings are founded in firm archaic mud below the soft mud deposited by distant placer mining in the late 19th century. Since even the archaic mud is too weak in this concentrated load application for conventional vertical friction piles, large diameter tubular piles were driven (inside the pumped-dry cofferdams) at angles, forming a "battered" (splayed) footing, through the archaic mud into the firm aggregated sand, mud, and gravel of the Alameda formation. Where long pilings were needed, segments were welded together as completed segments were installed. When all pilings were in place, a reinforced concrete pad was poured at the bottom of the cofferdam to form a footing for the column, subsequently cast in place around rebar using reusable metal formwork. A single viaduct segment located over each column was cast in place using forms. Pairs of precast span segments, fabricated in Stockton, were barged to the location and lifted into place with a specialized cantilever lift. (Cantilever lifts, counterweights and other equipment and materials were lifted either by a barge crane or by a jack-up crane located between adjacent columns.) Once in the proper location, the opposing segments could then be joined with through tendons (cables within conduits that are tensioned with jacks), forming a balanced cantilever over the column. Eventually, the gap in spans between columns was closed, forming a tendon-reinforced beam. The Oakland Touchdown is a curved elevated roadway that connects the skyway to the Oakland shore (the beginning of the bridge). The curve is required to bring the alignment to that of the existing ground-level approach road. Like the Yerba Buena Island Transition Structure (YBITS) to the west of the main span, this section is also an end segment of the new