[pierreh]

This city journal will document the development of the "United Cities of Talaran", also known as "The Talaran cluster", under SimCity 4. It is a continuation/resumption of the city journal that existed on the Simmania site before that site's closure.

The development of the cluster started in October 2014. For many reasons, including a lack of available time, and until the end of last year a serious involvment in the RTMT project, the progress on the cluster has been quite slow. I run the Deluxe version of SC4 on a Windows 8.1 platform; the main mods are CAM 1, NAM (currently at NAM 36), and a very bastardized version of RTMT that is rather close to what should be RTMT V4. I run the Traffic Simulator with the Ultra setting.

The basic idea was to develop in parallel 9 cities, arranged on a 3x3 set of city tiles of the largest size. Since I am mostly interested in transportation matters with an emphasis on public transportation, I wanted to study the effect of the interconnection between multiple cities. I also wanted to explore the effects of 'pushing to the limits' on the game. The 9 city tiles, in their initial state, are shown here:




The terrain chosen has many bodies of water of various size and width, including a lake in Desognes. These waterways pose interesting challenges, especially when designing the global highway network. I decided to respect their layout and respective shapes, with very limited filling. Otherwise the terrain is essentially flat and the few small hills were flattened out - I am not very good when it comes to developing on slopes.

In order to avoid the dreadful "eternal commuter syndrom" that had plagued some of my earlier developments, I defined how the intercity connections should be set up:


The highway and the railway networks were laid out right at the start, respecting the connections as shown above, and they have essentially remained in place since then, with a few corrections, and some suppressions of unused railway lines. Later I started to add subway interconnections to reduce the bus traffic if possible - more about this later.

The highway network was based on RHW-6S. Meanwhile, the observation of traffic volumes has led me to widen some sections to RHW-8S and reduce other sections to RHW-4S or RHW-2. These changes are ongoing. There are no complete highway intersections requiring the use of full clover leaf setups; all highway junctions are of the T-type. Initially all these junctions were designed as partial cloverleafs (parclos) - this was mostly because I didn't know much about RHW at the time and was reluctant to delve into it. Here is a typical parclo:




Lately I have started a gradual replacement of the parclos by better interchanges, adapting the various ramps to the respective traffic volumes, and making use of FLEX features in NAM: For example:




In the cities, the surface road networks use, until now, exclusively the streets, roads and avenues supplied by Maxis. I have plans to upgrade some avenues to NWM networks to increase their traffic capacities. In general I do not use one-way roads because previous experiences with them were unsatisfactory.

With very few exceptions, where streets, roads and avenues need to cross highways, this is done with FLUP underpasses rather than overpasses; likewise, there are no surface crossings of railway tracks by roadways, FLUP underpasses are also used in those cases. Railway tracks cross highways with overpasses.


Public transportation within the cities is based on a combination of subway + tram (or: GLR) with buses acting as feeders. I use the 'German model', as implemented in particular in Köln, Düsseldorf and Hannover: trams run on roads and avenues in the residential and industrial areas, and enter tunnels to run as subways in the CBD. This is because I am a tram fan since my early youth and I like to see their automata running in my cities. All stations are RTMT stations and always feature a bus stop. I use tram on right-of-way sparingly.

Here is an example of GLR-on-avenue on 2 intersecting avenues, with a 'grand union' set of tracks inside the traffic circle, and a GLR+bus station on one of the branches, adjacent to the traffic circle:




In an area under developement, GLR-on-avenue tracks enter a GLR-to-subway transition to run as subway in the CBD on the right of the picture (this is an old picture, the area has most likely been developped in the meantime):




Because there is no 'tram-in-road' FLUP ramp, alternatives need to be used: the tram tracks leave the road and use a tram-to-subway transition to pass for example under railway tracks as a short stretch of subway. The following setup was required because of the 2 railway tracks:




In my city journal on Simmania I once posted a long rant about the way the subway was implemented in the game by Maxis. I won't reproduce that rant here. Suffice it to say that I think that Maxis did a poor job with that implementation, which severely limits realistic setups. I avoid what I call 'unrealistic setups', such as 2 subway tunnels crossing outside of stations, because of the impossible paths followed by commuters (and subway trains...) in those cases.


I don't spend much time and effort on eye candy stuff, but I like to keep my cities nice-looking (at least, to my eyes), and I place many parks and monuments of various kinds, to increase the desirability. This usually works out well. Because I want the highest possible traffic volumes, all areas are zoned with high density, including the residential areas (this means that you won't find in these cities the extended suburban areas with their individual houses; this is probably anathema - or at least, very strange - to most north-american players).


These were the design objectives for the cluster. Where are we close to four years later? The global view is this:




5 cities have populations of over one million Sims, and a 6th one is very close with about 999'000 Sims. One city has over 940'000 Sims, and there are 2 'laggards' with populations in the 660'000 range. Today the total population of the cluster is 8'811'188 Sims.


In general, 'region playing' works as described and discussed in countless threads and city journals in SC4-related forums - that is, not as well as one would expect. (I was warned about this many times, especially by my good friend Brian). The traffic figures across inter-city links (highways, railways, subways) are rarely matched, with sometimes glaring discrepancies. Some links that function well for many years suddenly become inactive.

I didn't pay enough attention to the following fact: when residents in a city look for a job, the boundary to a neighbor city is considered by the traffic simulator as the neighbor city itself - in other words since the simulator doesn't know what lies beyond the boundary it 'assumes' that the boundary is the neighbor city. When the distance between a given residential building and the inter-city link is shorter than that between the building and a commercial or industrial area in the same city, the Sims in the residential building will be sent to the inter-city link to find a job.

The (quite sound) advice is to zone the residential areas so that the distance between those areas and the CBD or an industrial zone is shorter than the distance to an inter-city link. I generally overlooked this when zoning, and this has led to various difficult traffic situations in some cities.


Then there is the issue of 'pass-thru commuting', that I illustrated with the following picture:



It shows the 3 cities of Arcens, Deramey and Cherenne. In blue the defined inter-city links as per the global links picture shown earlier. In red, the 'pass-thru commuting' between Arcens and Cherenne, that is made possible by the defined links. In the course of the development of the cities, such commuting has generated very high volumes of traffic on the highway and railway in the median city, here in Deramey.

In this particular case, I implemented a direct subway connection between Arcens and Cherenne, with a subway tunnel but no station in Deramey. That direct subway connection became rapidly saturated, so that a second one, and later a third one, were placed. The usage is not yet well spread between the 3 connections:




There are currently several further cases of saturation of inter-city connections in the cluster, which need to be addressed. This is on my to-do list. A special case is Arcens, which sits in the middle of the cluster, and must support pass-thru commuting between all other cities, in addition to its own inter-city commuting with its immediate neighbors.

I expected Arcens, because of its central location, to prosper due to the numerous links with the other cities. In fact, Arcens has consistently lagged behind the other cities in terms of development, and has remained the least populated city. To a limited extent it is due to the surface of the city tile occupied by water, leaving less land for zoning. But the main reason, I think, is the way I zoned the various areas, as illustrated here:


Nearly all residential zones (green) are closer to the city boundaries than to the CBD: SIms tend to 'escape' to the neighboring cities to find work, and Arcens' CBD doesn't develop as well as it should.


Another case of sub-optimal development is that of Polsay. Here the geography, with the very large body of water separating the two land masses, plays a role. Essentially, two separate cities have developped, one on each piece of land. Although bridges for highway, avenue or road, and railway have been provided, as well as metro tunnels, traffic between the two parts remains extremely low, close to nil for some modes of transportation.



The city is mostly built, so that its population won't grow much beyond what it is currently. Still, Polsay plays an important role for pass-thru traffic, therefore its infrastructures will need close observation and upgrades where required.


In general, inter-city railway traffic is unsatisfactory. Some links are heavily used, to the point of saturation, while other links see very little usage, and I haven't been able to identify why this is so. (Admittedly I didn't spend much time looking into that).


Where inter-city railway traffic is low, inter-city bus traffic is usually high - way too high in some cases. Inter-city subway tunnels have been placed in attempts to reduce the loads on buses, This has worked only partially sofar, and a few situations are under close observation. Here is an extreme case observed at the border to Arcens in Marlande.



(By the way, I remember having a discussion with Brian about the interpretation of figures for buses and railways. Although the query produces 'Bus 55234', this cannot mean that there are 55234 buses per day going across the highway link. Spread evenly over 24 hours this would mean 38 buses per minute, or more than one bus every 2 seconds. Obviously we need to interpret the figure as '55234 Sims riding on buses every day'. Mind you, this is still a rather high figure: the articulated buses running in my home city of Geneva, model EVO O530G, have a theoretical capacity of 150 passengers (47 seating, 103 standing) but in reality with 120 passengers they are already very crowded. So let's assume an average 100 passengers per bus in the game, this is still 552 buses per day, or about 1 bus every 2 minutes 40 seconds, 24 hours per day. This is possible, although I fail to imagine the size of the bus fleet and the staffing requirements necessary to ensure the required service, but hey, this only a game...)


Then there is the dreaded 'limit' of 65535 'things to count'. This is because Maxis used many 16-bit counters in the game. (65535 = (2 power 16) minus 1). Since the game was released in 2003, we can't really blame Maxis for this, the developers probably thought that 16-bit counters were sufficient for the expected volumes. Still, this is quite annoying since, once the 'thing to count' (for example, cars, buses, in the above picture) reaches 65535, the counter ceases to work and all excess 'things' get dropped from the count.

This limit does not apply to all counters. For example, in the following query we can see that the maximal capacity of the Surbiton train station is 125'000, and the actual occupation is 268'311 (yielding a used capacity of 214% - this has been fixed since the picture was taken, I won't get into that fix here):



Still, the 65535 limit is encountered often and may force the layout of excessive infastructures.


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Further posts will of course not be as extensive as this introductory one. I'll try to post not too infrequently, and of course I'll reply to any queries related to this CJ.