In rural and suburban environments where street life is rare, the terms "street" and "road" are frequently considered interchangeable. Still, even here, what is called a "street" is usually a smaller thoroughfare, such as a road within a housing development feeding directly into individual driveways. In the last half of the 20th century these streets often abandoned the tradition of a rigid, rectangular grid, and instead were designed to discourage through traffic. This and other traffic calming methods provided quiet for families and play space for children. Adolescent suburbanites find, in attenuated form, the amenities of street life in shopping malls where vehicles are forbidden.