Editing Multiple nuclei model (section)

==Reasons for the model==

Harris and Ullman argued that cities do not grow around a single nucleus, but rather several separate nuclei. Each nucleus acts like a growth point.

The theory was formed based on the idea that people have greater movement due to increased car ownership. This increase of movement allows for the specialization of regional centers (e.g. [[heavy industry]], business parks, retail areas). The model is suitable for large, expanding cities. The number of nuclei around which the city expands depends upon situational as well as historical factors. Multiple nuclei develop because:
# Certain industrial activities require transportation facilities e.g. ports, railway stations, etc. to lower transportation costs.
# Various combinations of activities tend to be kept apart e.g. residential areas and airports, factories and parks, etc.
# Other activities are found together for their mutual advantage e.g. universities, bookstores and coffee shops, etc.
# Some facilities need to be set in specific areas in a city - for example, the CBD requires convenient traffic systems, and many factories need an abundant source of resources.