William Phelps Eno (June 3, 1858 – December 3, 1945) was an American businessman responsible for many of the earliest innovations in road safety and traffic control.[1] His rotary traffic plan was put into effect at Columbus Circle, New York City, in 1905, at the Arc de Triomphe in Paris, 1907, Piccadilly Circus in 1926, and the Rond Point on the Champs-Élysées in 1927.He attended Hopkins Grammar School in New Haven and Williston Academy, and graduated from Yale University in 1882, where he had been a member of Skull and Bones.In his 1920 book, Eno recalled that "in 1903, the New York Police Department asked that a plan be suggested for Columbus Circle, where accidents were occurring almost daily.Eno was awarded the cross of the Legion of Honour by the French government, and was one of the first honorary members of the Institute of Transportation Engineers.
Columbus Circle rotary plan in Eno's
Street Traffic Regulation
, 1909