The galactic city model, also known as the peripheral model, was created in the 1960s by Chauncy Harris who also co-authored the multiple nuclei model. Based on the city of Detroit, Michigan, the galactic city model shows a city that’s been taken over by a car based living and has been affected by urban sprawl. It has a rapidly growing suburb, and an increasing number of edge cities. A city that is based on this model is very decentralized, this is again due to urban sprawl.
In the center of the model is the CBD or central business district, it is where commercial businesses and companies locate. However, in this model, the CBD is very decentralized and empty due to the urban to suburban migration. Entertainment businesses and other services have moved out into the suburbs along with the urban to suburban migration too. These businesses concentrate in edge cities which are located at highway junctions. Large shopping centers are also located outside the CBD, usually they are spread out in the suburbs where the people are. Low income residents of the suburbs live near the industrial districts which are also near the highways. Then, located at highway junctions are also the office parks where the middle class citizens work. Office parks are located here because it is easier to get there by car and closer to the suburbs; not many people drive into the CBD everyday to work. Finally, there are the combined employment and shopping centers, this is where both offices and shopping malls are located.
Here is the link to the galactic city model: The Galactic City Model