Like much of New York City’s transportation infrastructure, Robert Moses had a hand in the planning and construction of the Brooklyn-Queens Expressway (BQE). The cantilever is the expressway’s most distinctive feature, and was built to conserve space and minimize intrusion in the surrounding neighborhood. It opened in 1954, although the idea dates back the 1820’s with a proposal by Hezekiah Pierrepont to create a private garden looking towards Manhattan to rival Battery Park. Moses would not consent to making the area private, but did ultimately create a public Promenade atop four-tenths of the cantilevered highway.
"This 8-block, 3-level cantilevered structure is significant as an innovative solution for constructing a modern highway while preserving the integrity of Brooklyn Heights neighborhood and preserving area views of Manhattan. The esplanade contributes to the Brooklyn Heights National Historic Landmark District."
-- Final List of Nationally and Exceptionally Significant Features of the Federal Interstate Highway System, FHWA USDOT