Urban design can be expressed as the three-dimensional relationship between buildings, open spaces, and streets within a given area. This visual expression of urban zones (combined with a specific plan that details where and what kind of development should occur) can determine the character of the community.

Currently, prevalent thinking on the subject of urban design is that new communities should be compact, mixed in both housing and commercial development, affordable, and pedestrian—a move back to living in compact, relatively self-sufficient communities and neighborhoods. It is a move back to a traditional community design in which communities and neighborhoods have affordable housing, jobs, and retail markets within easy walking distance for its residents.

This concept from the past is being promoted as the urban design and planning wave of the future. It addresses some of the ills that were brought about by the rapid suburban expansion after World War II: segregation of housing from workplace and retail areas, high housing costs, traffic congestion, long commutes, decay of community life, and negative environmental consequences (including air pollution and water pollution, inefficient use of energy and materials, etc.).

Proponents suggest that the move back to traditional urban design is good not only from the standpoint of promoting lost community values, but also positive for the environment. In fact, they submit that the environmental factors (such as the desire for clean air) will move the United States toward adopting this "new" approach. As the country addresses the issues of environmental quality, problems such as traffic congestion and affordable housing will become increasingly important to community design and planning, and will aid in the continuing evolution of urban design.