"Urban Design is concerned with the practice of designing, repurposing and revitalizing 3-dimensional places. These place types are described in Charter of the New Urbanism principles, as, “The neighborhood, the district, and the corridor are the essential elements of development and redevelopment in the metropolis. They form identifiable areas — centers, edges and in-between — that encourage citizens to take responsibility for their maintenance and evolution. Neighborhoods should be compact, pedestrian-friendly, and mixed-use. Districts generally emphasize a special single use, such as airports, campuses, and industry. Corridors are regional connectors of neighborhoods and districts; they range from boulevards and rail lines to rivers and parkways.”
Blackson goes on to discuss place types, comparisons between various cities, and concludes that the missing tool in most Cities are Neighborhood Units:
"Neighborhood Units have proven to make planning and design more manageable in Denver, Miami, and Ventura (cities that have recently implemented FBCs), but are still mostly missing from municipal policies and codes. Defining Neighborhood Units enables new development to make Community Character compatibility decisions versus 2-dimensional Land Use compatibility conformance findings."