Constructed to relieve traffic on the congested Boston Post Road, the Merritt Parkway quickly became one of America's premier roads, celebrated for its engineering and beauty. Its first segment opened in 1938 as Connecticut's first divided-lane, limited-access highway, free of trucks and advertising. Designed solely by the Connecticut Highway Department, construction began in 1934 and required extensive blasting of ridge tops and filling of valleys to carry an east-west road across north-south natural ridges and river valleys without creating a roller-coaster drive. Bridge construction and paving continued until completion in 1940, involving 2,000 workers and 14 private companies. George Dunkelberger of the Connecticut Highway Department designed the 72 original bridges, each unique and marked by styles ranging from Art Deco to Art Moderne; most were built of concrete to reduce costs, and he decorated them with sculptures, plants and animals on the abutments, and tinted concrete. Landscape architect Weld Thayer Chase designed a naturalistic setting to restore the beauty of the countryside, studying native plants before construction, preserving trees, replanting existing vegetation, and adding 70,000 purchased trees and shrubs along with thousands more donated by garden clubs and civic organizations. The road's significance has been recognized through listing on the National Register of Historic Places and designation as a State Scenic Road and a National Scenic Byway.