The Mount Vernon Avenue Association disbanded some time during World War I, but the concept of a Mount Vernon roadway was now championed by the federal Bureau of Public Roads (BPR). The BPR seized on the idea in the 1920s as a means of demonstrating the latest highway construction technology. Its first proposals were merely to upgrade the existing roads in the area and perhaps add a tree-lined boulevard, with formal, uninspired masonry bridges. But the BPR's proposals quickly evolved into much more. The agency hired Gilmore David Clarke and Jay Downer, who had designed the highly celebrated Central Westchester Parkway in New York, as consultants. They quickly proposed a more elaborate system of plantings, historic roadside pullouts, and scenic overlooks, and a more sinuous road design. The BPR began calling the road a "highway" rather than a parkway to de-emphasize its commemorative nature in the hope that Congress would fund its construction.