Patented in the United States by Maryland civil engineer Arthur Hale on February 29, 1916, the cloverleaf interchange was designed in the early days of motoring to keep traffic flowing smoothly through an intersection without traffic signals. The first cloverleaf interchange built in the U.S. was the Woodbridge Cloverleaf, which opened in 1929 at Route 25 and Route 4, now Route 1/9 and Route 35. Modeled after a plan from Buenos Aires, Argentina, and designed by Rudolph and Delano engineers of Philadelphia, it was praised by Engineering News-Record in 1931 as an outstanding development in traffic engineering. Listed on the National Register of Historic Places, it later became obsolete as traffic volumes increased, and in 2006 the New Jersey Department of Transportation demolished it and began constructing a modified partial cloverleaf interchange at the same location.