Regions

Great post! (Although not all of it strictly region-related ;) ) Some excellent points, but also a few things I would disagree on:

1) All natural resources in a region are availabe to all cities in the region.

Agreed, although I think this oversimplifies things a bit; I want to stay away from the resource "daisy-chain" paradigm that so many other city builders use (e.g., you need ore to make iron to make tools). That's out of place for a modern city sim. Instead of working on a basis of "availability", proximity to natural resources should confer advantages in terms of their price.

2) Cities are 10kmx10km and neighborhoods are 1km^2
3) All regions need at least one city and can have up to 100 independant neighborhoods (townlets)

I have to disagree on this, for a couple reasons: first, it seems to presume that cities/regions will be square, which I want to move past. Second, it's arbitrary and doesn't reflect the wide variations in city size IRL. Last, I think it's important that city boundaries be dynamic; real life municipalities grow and change size, or even disappear as they are absorbed into larger urban conglomerations. I want the in-game divisions between neighborhood, city, and region to reflect that.

4) All 100 neighborhoods of a city share utilities and share the same funds but taxes can be adjusted individually in neighborhood mode (although, tax changes in city mode change all taxes in all neighborhoods)

This, definitely. Having a separate power plant for each little town in SC4 was absurd.

5) Neighbor deals are done between cities and/or townlets and require the same infrastructure as SC4 but special neighbor deals can be traded between cities with ports (airfields and harbors).

If we're sharing utilities region-wide, what would they have to make deals about? Making deals with neighboring regions would make more sense. Naturally, the infrastructure should have to be in place for a town to take advantage of those regional services.

6) Citizens can commute by road, rapid transit, airplane, or ferry and can go on vacations using cruise ships (in addition to other methods).

Yes. municipal boundaries shouldn't play into the considerations for commuting at all. But I don't think it's worth it to actually model individual citizen's vacations; that should be abstracted in the general calculations for productivity, leisure satisfaction, etc.

7) Demand is dependant on pre-existing structures (citizens want employment and businesses want customers and workers) and resource surplus/deficit

Not quite sure what you mean by "pre-existing structures"; But I do want to stress that the focus should be on resource price rather than surplus/deficit on the supply side. That is, low availability of a resource (not produced locally, bad infrastructure for import) would be reflected in a high price, which would then result in businesses relying on the resource as an input being less profitable.

8) Demand can be manipulated by trading resources in city or regional mode

See above. I want to steer clear of this model. Sourcing natural resources, especially for private businesses, is far, far outside the province of any urban planner or city mayor.

9) International (beyond region) commuting and vacationing (movement/trading of people and holidays) require International Airports or Cruise Ships (or rapid aquatic transport) on bodies of water that have deep areas at the border of the region (bodies of water that extend beyond the region)

Not sure how useful it is to model this, as people who regularly commute to totally different metropolitan areas from where they live are probably something of an statistical outlier. As for holidays, see my point above. I think instead we should abstract the effect of transport infrastructure on business/leisure. One important point to make here, though, is that the effects from inter-regional transport (airports, highways, etc.) should extend across the entire region.

10) Regions can collect taxes and provide regional or inter-city services but combined taxes can be no more than 75%
a. There might be a national or planetary government that can provide high quality services and high paying jobs and collect additional taxes but combined taxes can never be more than 75%

I definitely agree that there must be different levels of tax authority that have responsibility for different areas of spending; An abstracted national government which collects taxes could also have jurisdiction over things like national highways (like the Interstate system in the U.S.) Why arbitrarily cap it at 75% though? In the 1950s the top bracket tax rates in the U.S. were almost 90%! I think you should be able to push it all the way up to 100% and watch a bloody revolt break out :)

b. By default all citizen taxes are set to 10% industry/business taxes set to 15% and shops/commercial service taxes set to 5%.

Is that including the national taxes? I want to live in your city! :D

11) Prices of neighbor deals by default are 10% higher than the cost to produce the resources/utilties/etc but money can be exchanged outside of those neighbor deals (with total traded money per entity being the only thing that shows up in the main trade and budget menues)

Again, I think this whole Cities XL paradigm of trading resources doesn't make much sense. For utilities I think you're spot on, though!

12) Pollution comes in four types: noise local (area of effect but cannot pass between cities or townlets), city (or townlet) wide, and Carbon Dioxide (regional wide).

To clarify: is that "noise/local/citywide/CO2" as the four types? Are local and citywide measures of just air quality, or do they encompass water pollution as well? I agree that noise pollution should be included, but I question whether a separate value for C02 (assuming that's distinct from regular ol' air pollution) really makes sense on this scale. Certainly worth considering though.

a. Trees absorb CO2 so they lower Carbon Dioxide levels to bright green; water and special buildings do also. Some special building can lower carbon dioxide levels to clear (if you go overboard) but that would kill plants.
b. Special parks can lower city wide pollution by up to 90% each (but usually lower than that, which means city wide pollution can never be completely removed)
c. Really special parks can lower local pollution by up to 20% each.
d. Health levels lower when local or city wide pollution levels increase in residential area.
e. Traffic causes noise pollution and low tech traffic also causes local pollution and Carbon Dioxide.

Trees improving air quality makes sense and has a basis in fact; But I don't like the idea of "special" parks sucking up pollution. Parks should help the air quality at the same rate as any other wooded area, or even less, if they are more grass than forest. Even so, I think the benefits to air quality from trees should be fairly limited, as IRL. The only way to truly reduce pollution in one's city should be with strict environmental regulations, which carry a corresponding economic penalty.

13) Weather is dependant on chosen climate, disaster settings, and Carbon Dioxide levels. Unless disasters are set to always off no matter what (which means the player cannot make disasters), natural disasters will occur if Carbon Dioxide is in the red. Some Natural Disasters can affect the whole region. Some Natural Disasters can terraform.

Again, I'm not sure if modelling changes in weather patterns from CO2 buildup is really within the scope of a city sim. I think climate would be a much more important consideration.

14) Terraforming can be done on the neighborhood, city, or regional modes with regional modes causing no uneven terrain between cities but being the biggest and clunkiest.

Absolutely, although there's no need for the regional terraforming to be big and clunky; In fact, I don't think there needs to be any kind of distinction between them, district boundaries should be a completely separate layer from the underlying terrain.

Lots to think about here... I think modelling "levels" (neighborhood, city, region) and having them all fit together smoothly is possibly the biggest design challenge of the game.

I thought that local pollution could also include water pollution but maybe water pollution should be seperate. Sewage treatment and water treatment can lower pollution with buildings hooked up to sewage lines not causing water pollution and having all the water pollution end up at the end of the sewage lines (unless there is waste water treatment/sewage treatment). Water purification plants produce water and lower water pollution and work regardless of pollution level.
I acidentilly said that special parks lowers city wide air pollution by 90% instead of lowering pollution by 10%. Very special parks can lower local and city wide pollution by up to 20% each for each park. All parks lower CO2 because they have plants but different trees, bushes, grasses and other plants lower CO2 at different levels.
I should also add that if CO2 levels reach black levels, you loose the game unless you evacuated your population with space ports.
Modelling CO2 has been done. SimCity Societies did it to an extreme.
Neighbor deals exist between different cities on a region and other trade deals can be done between any cities or regions on a planet. Any type of trade deal is to quanticize what is going over borders. Something I disliked about SimCity 4 is that demand based on wealth and education levels dictates everything that grows. I think it is unrealistic to have no heavy/dirty or manufacturing industry at all. I think that everyone should have to make supportive industrial cities but make sure that there is not too much low tech level industry.
I think that pollution emission should be based on tech level (year/EQ) and special buildings. Everybody starts out with a tech level of 0 and the maximum tech level is 500 but beyond 100, things get so advanced and efficient that it does not really matter and it gets harder to raise tech level beyond 100. A tech level of 500 would require all cities in a region to have maxed out EQs (education quotients of 200), the region producing at least 500 tokens of high tech industry, and the year of the region being at least 500.
A region can have 3 cities and 10 townlets and still be valid rectangle under my recommendations. If you recommend that the number of townlets maximum be raised, it is fine with me. I think that it would be best if a region was rectangular but I guess it could be an irregular shape with townlets jutting out at random and there being empty spaces without cities or townlets just like in SimCity 4. If you propose on more sizes of independant townlets, then maybe there could also be sizes up to 5km by 5km.

I thought that local pollution could also include water pollution but maybe water pollution should be seperate. Sewage treatment and water treatment can lower pollution with buildings hooked up to sewage lines not causing water pollution and having all the water pollution end up at the end of the sewage lines (unless there is waste water treatment/sewage treatment). Water purification plants produce water and lower water pollution and work regardless of pollution level.

I agree... water pollution has different causes and spreads differently than air pollution. I think it's also important to model surface water pollution and aquifer contamination separately.

I acidentilly said that special parks lowers city wide air pollution by 90% instead of lowering pollution by 10%. Very special parks can lower local and city wide pollution by up to 20% each for each park. All parks lower CO2 because they have plants but different trees, bushes, grasses and other plants lower CO2 at different levels.

That sounds like a more reasonable level... But I think the best way to approach it is that there is a cumulative maximum reduction of air pollution levels of up to 20% or 30%, dependent on the ratio of tree cover to developed areas in your city. That is, at a 1 to 1 ratio of forest land (including parks and roadside trees) to development, your overall pollution would be reduced by 20%. Any further trees would have no effect, and the only way to reduce pollution levels beyond that is to deal with the pollution's source.

I should also add that if CO2 levels reach black levels, you loose the game unless you evacuated your population with space ports.
Modelling CO2 has been done. SimCity Societies did it to an extreme.

I guess my question is, why split out CO2 as a separate category from other types of air pollution? And while I think excess pollution should result in losing the game, I don't think it should be because of an arbitrary loss condition; Pollution should cause you to lose the game because no one wants to live in your city and everyone moves out.

Neighbor deals exist between different cities on a region and other trade deals can be done between any cities or regions on a planet. Any type of trade deal is to quanticize what is going over borders.

I question why this is necessary. We've established that cities in the same region are already sharing utilities, so there's no need for them to trade anything between themselves. And as for resources and trade goods, there's no reason why the player should have to manage that. That would be like if, IRL, the mayor of Cleveland needed to sign an agreement with the mayor of Philadelphia for companies in each city to do business with each other; It just doesn't make sense. Nations do make trade deals with other nations, but that's outside the scope of the game.

Something I disliked about SimCity 4 is that demand based on wealth and education levels dictates everything that grows. I think it is unrealistic to have no heavy/dirty or manufacturing industry at all. I think that everyone should have to make supportive industrial cities but make sure that there is not too much low tech level industry.

You're right that SC4's economic model was unrealistic; But be careful not to conflate "dirty" and "heavy" industry as if they are the same thing. I agree that any economy needs heavy industry, but that doesn't mean it has to be dirty; by the same token, high-tech industry isn't necessarily clean either (Look at China's high-tech sector, it's hardly a model of ecological responsibility.) Instead they should be two separate metrics, with the "cleanliness" of industry dependent on technology and regulation (which means lower profit margins).

Also, while I agree that heavy industry has to exist somewhere I don't think it should be incumbent on the player to build heavy industry in their own region; The lack of local availability should just be reflected in the price of industrial goods for consumer and businesses.

I think that pollution emission should be based on tech level (year/EQ) and special buildings. Everybody starts out with a tech level of 0 and the maximum tech level is 500 but beyond 100, things get so advanced and efficient that it does not really matter and it gets harder to raise tech level beyond 100. A tech level of 500 would require all cities in a region to have maxed out EQs (education quotients of 200), the region producing at least 500 tokens of high tech industry, and the year of the region being at least 500.

Good idea! I definitely want to incorporate tech development in some way; I always liked that in the older Sim Cities.

A region can have 3 cities and 10 townlets and still be valid rectangle under my recommendations. If you recommend that the number of townlets maximum be raised, it is fine with me. I think that it would be best if a region was rectangular but I guess it could be an irregular shape with townlets jutting out at random and there being empty spaces without cities or townlets just like in SimCity 4. If you propose on more sizes of independant townlets, then maybe there could also be sizes up to 5km by 5km.

Sorry, should have elaborated my previous comment a bit better; What I mean by not making cities and regions square is that they can have irregular shapes, not just quadrilaterals. Like this, for example:

County Map of New Jersey

Also, why put a hard limit on the number on the number of subdivisions in a region or city? Let the player create as many as their computer can handle.

I still think that for cheaters, there should be a way to unlock secret special parks that clean the air like SimCity 4 parks. The first special parks can only lower city wide pollution but the best of them can lower city wide pollution by up to 10% but their trees can lower CO2. The second tier of special parks can lower local (air) pollution with the best of them lowering local pollution by up to 20%. This means that the player can never completely remove pollution and that the more parks he places, the less additive effect they have. So lets say we have a special park that lowers city wide and local air pollution by 10% for each (large) park. The air pollution level would drop to 90%, then 81%, then 72.9%, then 65.6%, then 59%, then 53.1%, et cetera until you run out of room for parks within the area of effect. Regular parks would lower local air pollution by 1-5% each so the difference is negligible. In SimCity 4, you had a loss condition where if your budget goes too far into a deficit, you lose and run for senator. It has occured to me once, the good thing was that I saved it a long time before the loss and I was running the game at fast speed. I cut expenses on services to minimal and expenses to transportation to 90% and I quickly made a lot of money without raising taxes. In LinCity, the player loses if population drops below 2 (which usually only happens in heavilly polluted cities) but the player wins if he evacuates enough people to space.
 
I think that there should be no limit on the number of (10kmx10km) cities in a region but I think that independant townlets should have a limit because of how many save files would be in a region. Either that or have it so that any section of a region with 10x10 independant townlets (1x1km each) becomes 1 main city (10x10km). I think that it would be easier (to program) if regions were made up of rectangular pieces (cities and townlets). In SimCity 4, regions had rectangular config.bmp files but the actual appearence could be different if there were black sections (or there were blue sections that were not multiples of 4x4px). I recommend using a config.bmp to simplify things (white being a big city, black being nothing, red being townlet--green and blue could be bigger towns).
 
If you think that it would be best if utilities were shared accross the entire region, then I guess trade deals would be unneccessary for utilities but I thought that each independant city or townlet had to make a deal but every neighborhood of a city sharing utilities. Some SimCity Regions are less than 10x10km so it made sense to me. Here, the minimum size of a region would have to be 10x10km but the maximum size would be limitless. Here in the Pacific Northwest, different cities have different power companies and each power company buy from a different combination of electric sources (the Puget Sound gets most of its electricity from the Grand Coulie Dam (Seattle gets its power almost exclusively from the dam and gets first dibs) but gas and renewables are used also, the TriCities get their power from the Hanford Nuclear Power Plant, the Columbia River gets its power from coal and small dams). If we impliment regional and municipal governments as seperate entities, regional utilities would be shared but municipal utilities would be exclusive/traded according to my proposal.
I think that there should be a way to see what is going over borders. Businesses could do the majority of trading but I want to see what resources are being produced, consumed, and traded. I think that by default, resources would be bought and sold on the planetary market place by businesses but maybe there could be an option that would allow players micromanaging and extra control on demand. I think that there should also be an entity that only the player can trade with that would buy or sell any resource regardless of the market, with fixed (and unfair in a balanced market/economy) pricing in case a player wants to make a region or planet with a completely unrealistic market balance without too much trouble).
 
About tech level, Heavy Industry at tech level 0 would be the worst polluting and High Tech Industry at technology level 200 and above would not pollute at all. Offices will always be the least polluting (polluting the same as housing). But Offices would require a lot of resources and utilities at low tech levels (tech level 0-25 would have less electricity demand, until Offices get so high tech that they become super efficient and produce their own power at tech level 250). High Tech Industry would require a tech level of at least 25 (or 50) to unlock (or grow) but would be pretty high polluting and unpopular (low demand and low usage) until the tech level increases. High Tech recycling facilties and trash to plasma converters would produce Heavy Industry products so after tech level 200, heavy industry would not be needed so much. At tech level 500, most demand for industry would be high tech industry (about 95%) with demand for heavy industry being 0% (because there would be new high tech methods of producing heavy industrial products). The consumption of heavy industrial products will be lower but still be there and the demand for manufactured goods would not drop too low but the consumption of High Tech industry would jump through the roof (imagine every person, rich and poor, having a laptop, smartphone, and portable entertainment device and everyone living in smarthouses with super energy efficient, networked appliances and fuel cells).
 
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My idea for a city simulator would have some functionality of SimCity 4 (backbone), SimCity Societies (weather and pollution), Cities XL (market balance and manipulation of it), SimCountry (market balance having an effect on prices), LinCity (tech level and balanced economy and ecosystem) and SimCity 2000/3000 (weather statistics having effect on renewable resources and water production and year, or in our case tech level). There is a browser game that has a lot of these statistics and nothing else (which means it has all the data from all these games combined to a certain extent but has absolutely none of the playability of an actual game, pretty much). I tested it out for a week but I stopped playing it quickly.

About taxes, SimCity 4 had all taxes by default at 9%, and Cities XL had residential taxes at 10%, shops taxes at 10%, and corporate taxes at 15%. SimCity 4 had a cap at 20% and Cities XL had a cap at 75%. Here, we have property tax (for everyone), corporate taxes, and sales tax (if you add up city, county and state taxes it is 11%). Maybe you would reccommend that default would be 10% for residents and shops and 20% for corporations (we have tax breaks so our tax level is lower than 20%). Maybe we could choose to charge people and businesses for utilities also (by default 10% lower than it costs to produce it).
[Possible] Sources of income (add any if you think of anything):
Income (residential) tax
Corporate tax
Sales tax
Property Tax ordinance (adds 1-5% of a buildings value to treasury when it grows/is developed in the private market)
Buying and Selling property (you mentioned this earlier)
Exports
Toll Roads
Mass transit fares (usually makes less money than it earns)
Charging for utilities___________________________maybe not the ones below____________________
Nationalized businesses (can be offices, factories, shops, restaurants, and leisure providers)
Corruption (police and beaurocracy suddenly stop costing the city and start making money)
Bonds (needs a treasury) and Loans (needs a bank) (depending on direction, could make or lose money)

I still think that for cheaters, there should be a way to unlock secret special parks that clean the air like SimCity 4 parks. The first special parks can only lower city wide pollution but the best of them can lower city wide pollution by up to 10% but their trees can lower CO2. The second tier of special parks can lower local (air) pollution with the best of them lowering local pollution by up to 20%. This means that the player can never completely remove pollution and that the more parks he places, the less additive effect they have. So lets say we have a special park that lowers city wide and local air pollution by 10% for each (large) park. The air pollution level would drop to 90%, then 81%, then 72.9%, then 65.6%, then 59%, then 53.1%, et cetera until you run out of room for parks within the area of effect. Regular parks would lower local air pollution by 1-5% each so the difference is negligible.

I see what you meant (although frankly I think parks should work on an area basis rather than as discrete units). I'm still wondering what the rationale would be for making "air pollution" and "CO2" separate categories.

In SimCity 4, you had a loss condition where if your budget goes too far into a deficit, you lose and run for senator. It has occured to me once, the good thing was that I saved it a long time before the loss and I was running the game at fast speed. I cut expenses on services to minimal and expenses to transportation to 90% and I quickly made a lot of money without raising taxes. In LinCity, the player loses if population drops below 2 (which usually only happens in heavilly polluted cities) but the player wins if he evacuates enough people to space.

Exactly, the city should fail if people move away or the municipality goes bankrupt from mismanagement, rather than creating an arbitrary "too much pollution" loss condition.

I think that there should be no limit on the number of (10kmx10km) cities in a region but I think that independant townlets should have a limit because of how many save files would be in a region. Either that or have it so that any section of a region with 10x10 independant townlets (1x1km each) becomes 1 main city (10x10km). I think that it would be easier (to program) if regions were made up of rectangular pieces (cities and townlets). In SimCity 4, regions had rectangular config.bmp files but the actual appearence could be different if there were black sections (or there were blue sections that were not multiples of 4x4px). I recommend using a config.bmp to simplify things (white being a big city, black being nothing, red being townlet--green and blue could be bigger towns).

I really don't think there's any good reason to keep cities square if we're not using a grid system (it wouldn't even be "easier to program" in that case, the whole reason for using rectangular cities in SC4 was because of the grid.) There's no point in trying to make a new game if we're going to make it just like SC4.

If you think that it would be best if utilities were shared accross the entire region, then I guess trade deals would be unneccessary for utilities but I thought that each independant city or townlet had to make a deal but every neighborhood of a city sharing utilities. Some SimCity Regions are less than 10x10km so it made sense to me. Here, the minimum size of a region would have to be 10x10km but the maximum size would be limitless. Here in the Pacific Northwest, different cities have different power companies and each power company buy from a different combination of electric sources (the Puget Sound gets most of its electricity from the Grand Coulie Dam (Seattle gets its power almost exclusively from the dam and gets first dibs) but gas and renewables are used also, the TriCities get their power from the Hanford Nuclear Power Plant, the Columbia River gets its power from coal and small dams). If we impliment regional and municipal governments as seperate entities, regional utilities would be shared but municipal utilities would be exclusive/traded according to my proposal.

I suppose it would be possible to implement utilities for various levels of government... so you could start with smaller scale facilities and later build a big nuke plant or dam for the whole region.

think that there should be a way to see what is going over borders. Businesses could do the majority of trading but I want to see what resources are being produced, consumed, and traded. I think that by default, resources would be bought and sold on the planetary market place by businesses but maybe there could be an option that would allow players micromanaging and extra control on demand. I think that there should also be an entity that only the player can trade with that would buy or sell any resource regardless of the market, with fixed (and unfair in a balanced market/economy) pricing in case a player wants to make a region or planet with a completely unrealistic market balance without too much trouble).

Again, unless we're talking about our regions being autonomous nation states, this doesn't make any sense; no one's keeping a record of what goes over the border from Illinois to Missouri. What we should be shooting for is to have a realistic economic model with realistic economic data.

About tech level, Heavy Industry at tech level 0 would be the worst polluting and High Tech Industry at technology level 200 and above would not pollute at all. Offices will always be the least polluting (polluting the same as housing). But Offices would require a lot of resources and utilities at low tech levels (tech level 0-25 would have less electricity demand, until Offices get so high tech that they become super efficient and produce their own power at tech level 250). High Tech Industry would require a tech level of at least 25 (or 50) to unlock (or grow) but would be pretty high polluting and unpopular (low demand and low usage) until the tech level increases. High Tech recycling facilties and trash to plasma converters would produce Heavy Industry products so after tech level 200, heavy industry would not be needed so much. At tech level 500, most demand for industry would be high tech industry (about 95%) with demand for heavy industry being 0% (because there would be new high tech methods of producing heavy industrial products). The consumption of heavy industrial products will be lower but still be there and the demand for manufactured goods would not drop too low but the consumption of High Tech industry would jump through the roof (imagine every person, rich and poor, having a laptop, smartphone, and portable entertainment device and everyone living in smarthouses with super energy efficient, networked appliances and fuel cells).

Not following you here... laptops and smartphones *are* manufactured goods, last time I checked...

About taxes, SimCity 4 had all taxes by default at 9%, and Cities XL had residential taxes at 10%, shops taxes at 10%, and corporate taxes at 15%. SimCity 4 had a cap at 20% and Cities XL had a cap at 75%. Here, we have property tax (for everyone), corporate taxes, and sales tax (if you add up city, county and state taxes it is 11%). Maybe you would reccommend that default would be 10% for residents and shops and 20% for corporations (we have tax breaks so our tax level is lower than 20%). Maybe we could choose to charge people and businesses for utilities also (by default 10% lower than it costs to produce it).

I think it would depend on how much control the player has over the national and regional tax rates; What the default is doesn't really matter anyway, since the player can adjust it. By the way, why would the utilities run at a loss?

[Possible] Sources of income (add any if you think of anything):
Income (residential) tax
Corporate tax
Sales tax
Property Tax ordinance (adds 1-5% of a buildings value to treasury when it grows/is developed in the private market)
Buying and Selling property (you mentioned this earlier)
Exports
Toll Roads
Mass transit fares (usually makes less money than it earns)
Charging for utilities___________________________maybe not the ones below____________________
Nationalized businesses (can be offices, factories, shops, restaurants, and leisure providers)
Corruption (police and beaurocracy suddenly stop costing the city and start making money)
Bonds (needs a treasury) and Loans (needs a bank) (depending on direction, could make or lose money)

Well, income taxes (corporate or individual) and sales taxes are almost never levied on the local level, and export tariffs only apply to national governments. Bonds aren't exactly a source of income, they're just a form of loan against future income. And corruption? That makes no sense at all, it's not like corrupt cops pass their bribes on to the city treasury :) If anything, corruption would mean a decrease in effectiveness while paying the same costs.

For most municipalities, the bulk of their income is from property taxes; Municipally-owned services, including transit and toll roads, are also good possibilities: I don't see why they would "usually make less money than [they] earn".

 When you say you want to move past square regions I completely agree. So what if the city boundary was dynamic? Lets say you are presented with a world/area and you choose a location to build your city by clicking on a point. After some cool cinematic zooming you are presented with a circular area with a radius of say 2.5km (or something similar) and around that area the view fades to black. A sort of fog of war type arrangement. Now you begin developing you city and as you do so you build towards this boundary and the boundary in turn shifts outwards always remaining a set distance from you actual city edge. The city edge could be defined as any and all constructs, buildings, parks, road etc. This would pose no problem for placing a structure away from the main city body providing you first built a road to it, which to be honest every structure realistically needs (workers need to get to work). This then allows a city to expand or shrink as the player so desires. In terms of regions and inter-city connections here's what I would like to propose. When two cities approach each other's boundaries they become visible, meaning if you were playing one city the passive city's outer limits would be visible within your boundary marked perhaps by a line or shading of the structures. You can construct up to this line, allowing you to make transport and utility links. Once two or more cities are linked this becomes a region. Within a world there could be many regions. regions are therefore also dynamic in size.
Clearly the idea needs some work so I was hoping you guys would consider it. It's only a small part but it is only my first contribution.

Hi SilverGizmo, and welcome to the forums! Very cool idea; this is exactly the kind of approach I had in mind. I especially like how it addresses the problem of boundaries by tying them to the city's organic growth patterns, at least in the initial stages. If you think of the new cities as being settlements in virgin territory, it gels with the way such settlements would naturally define their boundaries (like, "Old Man Wallis's house marks the edge of town" :) ) I would also set it up so that you could set a fixed boundary manually if you wanted (if, say, you had a river or stream that you wanted to define the boundary of your city.) Definitely need to give some thought to how this would mesh with higher-level boundaries, i.e. regional and national, but I like the general concept.

The real problem with regions, as AzemOcram pointed out, is "the number of save files," or rather how we structure the simulation's focus; We can't have the whole world of cities being simulated at the same time; we really need to address the question of how neighbor cities behave when they're not "loaded", whether by doing it the way SC4 did with separate saves that develop independently, or some other way.