From Wikipedia: Construction had begun on Black Friday in 1929, and the Triborough project's outlook began to look bleak. Othmar Ammann's assistance was enlisted to help simplify the structure. Ammann had collapsed the original two-deck roadway into one, requiring lighter towers, and thus, lighter piers. These cost-saving revisions saved $10 million on the towers alone. Using New Deal money, the project was resurrected in the early 1930s by Robert Moses and the bridge was opened to traffic on July 11, 1936.