5. Buildings are disciplined on their lots in order to define public space successfully. The street is understood to be the pre-eminent form of public space, and the buildings that define it are expected to honor and embellish it.
6. The street pattern is conceived as a network in order to create the greatest number of alternative routes from one part of the neighborhood to another. This has the beneficial effect of relieving traffic congestion. The network may be a grid. Networks based on a grid must be modified by parks, squares, diagonals, T intersections, rotaries, and other devices that relieve the grid's tendency to monotonous regularity. The streets exist in a hierarchy from broad boulevards to narrow lanes and alleys. In a town or a city limited-access highways may exist only within a corridor, preferably in the form of parkways. Cul-de-sacs are strongly discouraged except under extraordinary circumstances -- for example, where rugged topography requires them.
7. Civic buildings, such as town halls, churches, schools, libraries, and museums, are placed on preferential building sites, such as the frontage of squares, in neighborhood centers, and where street vistas terminate, in order to serve as landmarks and reinforce their symbolic importance. Buildings define parks and squares, which are distributed throughout the neighborhood and appropriately designed for recreation, repose, periodic commercial uses, and special events such as political meetings, concerts, theatricals, exhibitions, and fairs. Because streets will differ in importance, scale, and quality, what is appropriate for a part of town with small houses may not be appropriate as the town's main shopping street. These distinctions are properly expressed by physical design.
8. In the absence of a consensus about the appropriate decoration of buildings, an architectural code may be devised to establish some fundamental unities of massing, fenestration, materials, and roof pitch, within which many variations may function harmoniously.
Under the regime of zoning and the professional overspecialization that it fostered, all streets were made as wide as possible because the specialist in charge -- the traffic engineer -- was concerned solely with the movement of cars and trucks. In the process much of the traditional decor that made streets pleasant for people was gotten rid of. For instance, street trees were eliminated. Orderly rows of mature trees can improve even the most dismal street by softening hard edges and sunblasted bleakness. Under postwar engineering standards street trees were deemed a hazard to motorists and chopped down in many American towns.Accommodating
THE practice of maximizing car movement at the expense of all other concerns was applied with particular zeal to suburban housing subdivisions. Suburban streets were given the characteristics of county highways, though children played in them. Suburban developments notoriously lack parks. The spacious private lots were supposed to make up for the lack of parks, but children have a tendency to play in the street anyway -- bicycles and roller skates don't work well on the lawn. Out in the subdivisions, where trees along the sides of streets were often expressly forbidden, we see those asinine exercises in romantic landscaping that attempt to recapitulate the forest primeval in clumps of ornamental juniper. In a setting so inimical to walking, sidewalks were often deemed a waste of money. In the new urbanism the meaning of the street as the essential fabric of the public realm is restored. The space created is understood to function as an outdoor room, and building facades are understood to be street walls.