Spatial design is something that reveals the in built form the underlying social relations and it is society itself.

Following this logic we can say that city planning discloses a lot about society.
Modern urban planning began with segregation of activities. Earlier, the cities were organic in nature. Even then, it could be said that in organic cities too planning elements were present. The city planning catered to the needs of the people and reflected their routine and activities. The residence and work place became separate in the modern era

City planning reveals why something which is of benefit to the individual might not be beneficial for the society at large. For example, if each and every house extends into the lane there will be no street to walk on. Therefore, planning is necessary and the best cities are the best planned cities.