Constructed to relieve traffic on the congested Boston Post Road, the Merritt Parkway quickly became one of America's premier roads 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, the parkway began construction in 1934 as an east-west road crossing north-south ridges and river valleys, requiring extensive blasting of ridge tops and filling of valleys to avoid a roller-coaster-like drive. Bridge construction and paving continued until completion in 1940, involving 2,000 workers and 14 private companies. The 72 original bridges, designed by Connecticut Highway Department architect George Dunkelberger, were each unique and reflected styles from Art Deco to Art Moderne; most were concrete to reduce cost, and he embellished 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, saving and replanting existing vegetation, preserving selected trees, and adding 70,000 purchased trees and shrubs along with thousands more donated by garden clubs and civic organizations. He said his aim was to heal the landscape so nature could pull it all together in time. The Merritt Parkway has been recognized by listing on the National Register of Historic Places and designation as a State Scenic Road and a National Scenic Byway.