Expanding Cities

[3Styler]

Not sure if correct section, but anyway, all major cites expand and grow outwards as they develop right? so can someone please explain to me what kind of factors limit this continual growth outwards in the end and keeps a city at a constant size?

[Skids]

Most cities aren't a constant size.  Just about all cities and towns are continually expanding.

The main limiting factor is the space in which to expand.

[woofgang]

travel distances, cost of living/working there, sometimes sewage or water provision limitations, natural barriers, changes to the ecomonic profile of the city, changes to how the business of the city is done, eg e-banking

[woofgang]

oh and changes to what people perceive as a desireable way to live

[ianess]

3styler.....you have to turn your question on its head.  It's towns and villages that expand and merge thus forming cities.  I don't suppose that there is a limiting factor apart from the coastline in an outwards expansion, and they can always expand vertically like New York or Hong Kong.
I live in Central Scotland and it's amazing to see how villages are being swallowed up by towns.  Green belts are disappearing and in about 50 years we'll all be living in a concrete jungle. Terrible thought.

[OBonio]

There are supposed to be 'Green Belts' where no development is supposed to take plcae. These get turned on their heads if the local council smell a few quid to be earnt!

[3Styler]

yes i understand that greenbelts are there to try and prevent continual growth outwards,  but i was wondering that if purely hypothetically there was a city (ficticious city) and this city had to keep expanding outwards to cope with a continual growth in population, what kind of things would hinder the continual growth?

Vertical growth is a solution to growth outwards but why is such a solution required, not why are skyscrapers are good but more what the problem is with growing outwards?

Space as Skids said i believe must be correct, and woofgang is on the ball, thanks for that, are there other such factors, i'm jsut trying to understand why cities behave as they do.

[rampart]

I have a theory on that, Styler. The city starts with its central core of business and residences. As business grows outward, new housing forms at a further distance from the central business district.

In the course of several decades, a city will grow as wide as it can (assuming no natural limits such as water or mountains) until it reaches the limits of the households for their commute. That is, it will expand until the furthest homes have a commute of about one hour. Then the true core of the city stops.

There will be business that expands outward with the households as they migrate outwards, but that business is really more of the kinds that support the households (restaurants, laundries), but do not offer much high-income positions of which most have remained in the central district of the city.

When the houses in this outer ring of the city start to age and the people will expand housing no further out, the developers then look back at decrepit properties in the central district, and start leveling them to make new housing.

When the true industry (and therefore the jobs that carry the majority of the population) of the city is centralised, I believe it is a matter of how far the employees are willing to commute that limit the size of the city's growth.

[rampart]

To clarify as I re-read my comments -

When housing starts to return to the central district (that is, developers buy decrepit buildings, level them, and build new  housing), some of the workers' households are able to return to this area, and there is less pressure to keep expanding outward.

These cycles go back and forth, with households moving to their limits, then migrating back toward the middle.

You can only live where you can get work!

Anyway, that is my theory, for whatever it is worth.