[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.


-----------------


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.

[brian51]

Pierre,

what an amazing first posting for your CJ , my friend !!

I assume it was helpful you were able to still use pics and bits and pieces from your old CJ over on Simmania ?
Yet nevertheless , this still must have taken you a lot of time to put this entire epic first post together ?

One thing that is going to prove quite interesting which is apart from how i am currently playing the game and developing more a single city, .. is you are very much involved in regional play for the current time when playing SC-4

Than also because your using Z- ultra where I am using a custom traffic plugin file which is quite close to Z- medium, and also because you are very skilled with traffic patterns ( especially how you use mass transit), it is always a lot fun to see some of the amazing traffic figures your able to produce in your cities. And for example station usage figures , which i have never been able to equal..!!

i have a bit of a question / comment on this here :

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).

I dont think i ever knew this !
( one would have thought I should know from viewing so many pics from all your CJ 's thru the years !! )..
So i did know your cities of course were very high density, but not the consideration that ALL zones were high density.

So i assume this means there zoned as high density right from the start of your cities ?

if this is the case i think this is fine because as a player you are emphasizing function over eye candy.
In my case I would not be able to do this because of the high difficulties involved with using a traffic sim that is only about Z - medium.
And this does not mean you start off a city with light or medium density zoning and than change it later to alll high density .. I assume..

In closing though,
I really applaud your efforts on behalf of the site, for creating such a highly detailed and comprehensive first Cj  Posting here ..

[SpookyZalost]

interesting network design Pierreh, I usually just build one massive megacity in my effort to fill things with skyscrapers and multi-level highway networks in a cyberpunk style.
also anyone else notice that the Zone data view looks a lot like Simcity classic?

[Guardian]

This is phenomenal! Excellent planning, excellent thread, not to mention VERY impressive cities and region.

Thank you for sharing pierreh!

The region concept is one thing I wish was incorporated into Cities: Skylines. Hopefully in a DLC or sequel.

This does give me ideas, but sort of a different kind.

[Darth-Apple]

This is phenomenal! I echo Guardian's words, very well said! I've noticed you have some very nicely done highway, RHW, and rail networks. And quite a bit of bus traffic as well!

I'm greatly impressed with the scale and the detail across the region. When I did large regions I had a lot of trouble maintaining the outer cities at times. Your entire developed area is very well completed across the board. I'm greatly impressed!

Also thank you for posting your CJ here! Brian actually requested the section a couple months ago and we expanded it as per his suggestions (thank you @brian). It goes without saying that Simmania left a huge legacy for all of us and will be very greatly missed.

[pierreh]

(...) When I did large regions I had a lot of trouble maintaining the outer cities at times. Your entire developed area is very well completed across the board. I'm greatly impressed!

Actually, in the case of the Talaran cluster, it is the 4 cities in the extreme corners, that is, Desognes in the northwest corner, Cherenne in the northeast one, Prandergal in the southwest one, and Salveille in the southeast one, that have seen the best development and have the highest population counts.

It is possible that one reason for this is that each of those 4 cities has only one link to another city, and therefore its Sims tend to find work locally instead of commuting to other cities. But this is only conjecture on my part. The regional playing wasn't properly developed by Maxis, and we have to make do with its limitations and shortcomings.

[pierreh]

While playing the city of Marlande lately I looked in detail at the intercity traffic, and the way it affects that city. Like Deramey where the intercity traffic is briefly described in the initial post of this CJ, and like Polsay, Marlande has pass-thru traffic: in its case, between Arcens and Desognes:


Let's look at the road traffic first. There is a highway link between Arcens and Desognes, with an interchange in Marlande for local purposes. In the following traffic volume view, 1 is the link with Arcens, 2 is the main exit ramp from the highway to the city's surface road network, 3 is the link with Desognes.



It corresponds to this city view:



The main highway, linking Arcens and Desognes, uses RHW-8S. The highway segments are clearly heavily used. We can look at some figures at key points on the highway network, starting with the link with Arcens:




Adding up the numbers we get 15'638 cars and 49'422 buses. This is clearly 'too much' for a RHW-8S network (although this raises the general question: 'how much is too much?').

How many Sims are travelling, by car and by bus, in pass-thru mode from Arcens to Desognes? Taking numbers at the highway interchange in the city we obtain the following:




Adding up the numbers we get 17'381 cars and 17'415 buses. Here is a first surprise: there are more cars in the interchange, than there are at the link with Arcens, although there are no ramps between those two points, where some cars could be added to the flow. I ascribe this to the fact that the respective numbers result from counts that are dynamically tallied during the running of the game, so that a 'photography' of a specific instant in time cannot yield perfectly coherent numbers. What matters most here are the orders of magnitude of the traffic flows.

On the branch of the highway that continues straight to the city, we see:



More surprising, there are 4051 cars on that branch, bringing the total number of cars in the interchange to 21'435, much in excess of what was measured at the link. On the other hand, there are 23'802 buses, yielding a total of 'only' 41'217 buses in the interchange: we 'lost' buses between the link and the interchange, even if there are no intermediate ramps on which the buses could get off the highway. Let's not dwell on those discrepancies in numbers. (The branch, a RHW-4S, is clearly underdimensioned, an issue to address at some point).

All that traffic, that is, the 4051 cars and the 23'802 buses, exits in the same ramp a bit further in the city. The ramp is underdimensioned for the purpose, the size of the traffic flow wasn't expected.



Most if not all Sims travelling on the buses change to subway lines at the RTMT bus+subway combo station (circled) next to the traffic circle on the right of the picture. (A similar situation can be observed in Arcens where those Sims board buses at a combo station - this will be documented later).

At the other side of the highway, where it links to Desognes, we measure the following flows:




Adding up the numbers gives 31'448 cars and 33'954 buses (plus trucks). There are close to twice as many cars as on the link to Arcens, and there are less buses. We can assume that, in addition to the thru traffic, there is a good level of car traffic originating in Marlande.

Again, this appears to be 'too much' traffic for the RHW-8S.


Placing a subway link to reduce the load on buses hasn't been as successful sofar, as it is in the case of the direct traffic between Arcens and Cherenne, illustrated in my previous post. The situation is as follows:



The subway coming from Arcens (bottom right, 1) connects to another subway tube in a GLR+subway combo on the upper right of the picture (2); that second tube, with 2 further stations, links to Desognes on the upper left of the picture (3). There are GLR tracks connecting to the stations, that take traffic away from the subway lines.

Traffic is measured in the subway links: in the link to Arcens:



In the link to Desognes:



The flows appear rather balanced, but it would be very difficult to distinguish between thru traffic and traffic originating or terminating locally in Marlande.


There is also a direct rail link between Arcens and Desognes, bypassing the main railway station in Marlande. The link with Arcens does not see a high usage:



The link with Desognes, with dual pairs of tracks, has a higher usage:




The total usage here is 53'786. But if we look at the bypass tracks we see a rather low number of pass-thru train passengers (7473):



It appears that the bulk of train riders measured at the link with Marlande are boarding the trains at the main train station in Marlande. The usage of rail for pass-thru traffic is negligible.


There is a need to improve on the current traffic situation in Marlande. A widening of the main highway from RHW-8S to RHW-10S is possible (although the gain in performance is rather small) and a few branches and ramps should be upgraded. At the same time, the excessive usage of buses needs to be reduced. The subway layouts in the 3 cities involved will be reviewed, with the intent to increase the usage of the subway for intercity traffic. More about this, then, later...

[brian51]

Pierre,

thanks for your second CJ entry, which was just about as impressive as your debut CJ posting here at the site. ( perhaps more impressive than your first posting in the instructive sense) ..

Firstly, I felt you illustrated quite well some of the short comings of the game for regional play , in that you cannot expect exacting traffic figures all the time when one examines the various connections to cities and there traffic reported figures.. Although I think there was enough consistency in this regard to prove satisfactory for you ?

You do have some rather high traffic figures that are going thru some of the connections, but i think they are not so high that some adequate solution (tries) can be attempted as you have duly noted

You did  very nice job in describing the various traffic situations and issues you have involving these city connections as well as what you willl be attempting to do to try to alleviate some of the ( too high ) traffic conditions.

I will look forward to some future postings which give us some results of these well thought out traffic - solution attempts you will be implementing in the upcoming days and of course also your associated postings in that regard.. Which wlll show us how successful you will be with some of the traffic - solution goals you have in mind.

[pierreh]

In my previous post I showed the link between Arcens and Marlande, that is quite saturated. I also showed that the flow coming from Arcens goes partly to Desognes in pass-thru mode, and partly to the CBD of Marlande. That component of the flow exits the highway on a single ramp.

There is a similar situation in Arcens: the bulk of the traffic going to Marlande uses a single ramp, that is quite congested:




All the car traffic entering the highway via the ramp originates in residences on the east (= on the right) of the ramp. Presumably, for those residences the boundary to Marlande (which 'is' Marlande for the traffic simulator) is nearer than the proximate commercial zone in Arcens.




A similar situation is noted for the GLR and bus traffic: buses entering the highway via the ramp are boarded by Sims living in the residences on the east of the GLR+bus combo station. Some of the Sims use the GLR to arrive at the combo station (circled in black) where they change to intercity buses going to Marlande. Not a single Sim comes from the west (= from the left) side:




This means that it will not be easy to reduce the car and bus traffic on the intercity link between Arcens and Marlande.

[brian51]

Pierre,

thanks for your third posting in your CJ already,
which is really giving us a good idea how traffic works in regards to these inter city connections...

The east side of the highway seems to have a pretty large area of Residences over there. And so I am not surprised by looking at the development over there , that you can generate this much traffic on your networks.

Your pics do not show the commercial zone in Arcens, so yea i would assume that the commute to the jobs there must be a fair distance away. So it does look like the neighbor link  over to Marlande would be the closer option ( at least for Sims living on the east side.)

Not a single Sim comes from the west (= from the left) side:

I was just curious how far away are the residences on the West side of the city in relation to the neighbor connection ?

This means that it will not be easy to reduce the car and bus traffic on the intercity link between Arcens and Marlande.

I agree that it may be difficult to divert the traffic at this point to other optional job sites. But I do think you can engineer perhaps some additional options to handle traffic. Since there does not appear to be a lot of room for above ground networks, I would suggest perhaps subway and possibly underground rail  to try and handle a portion of the traffic to reduce congestion on some of the other networks.

What do you think of this plan ?

[pierreh]

I decided to implement a new subway intercity connection between Arcens and Marlande. The link was created in Marlande and appeared at the city boundary in Arcens:



Close to the boundary is a road with a tram-in-road (TIR), changing to a subway tunnel to pass under railway tracks. A GLR+bus combo (black circle) will be replaced by a GLR+subway combo moved to the right, with a roadside bus stop nearby.


The next picture is rotated to the left (north is on the right) to better show the part of the avenue on which the GLR+bus combo station is located, where the Sims board buses to Marlande. (The station has lost its GLR shelter - some silly prop issue that I am too lazy to fix). The ramp to the highway is immediately next to the station. The stats on the station show that it is quite overused, although still within tolerable limits:




The planned changes, extending to a longer stretch of the avenue, are shown in the next picture:



1 - new GLR-on-avenue to subway transition
2 - current GLR+bus combo station to be replaced by a subway+bus combo
3 - current GLR+subway+bus combo station to be replaced by a subway+bus combo
4 - new GLR-on-avenue to subway transition


The planned work was executed. This is the new subway view of the area (properly oriented):



1-4 as above; 5 is the new GLR+subway combo on the road close to the city boundary; 6 is the new subway tunnel linking to Marlande. At this time it terminates at the GLR+bus combo station near the highway ramp; it
may be extended further into Arcens later.


Here is the view of the avenue (rotated) with the changes implemented:




After running the city for a few game months there is already a decent traffic on the new subway link:




The next step will be to run Marlande to 'acquire' that traffic on the subway link.

--------------------

Brian, in answer to your question about the zoning, here is a zone view of Arcens:



1 - the residential area close to the boundary with Marlande, where Sims go mostly to work in Marlande
2 - residential areas that are closer to the nearby commercial area
3 - commercial area
(That part of Arcens is pretty self-contained, there is barely any traffic with zones on the other side of the large body of water).

[brian51]

Pierre,

Very nice construction project with well - thought out changes..

I though the subway choice was the best, correct and ( if not obvious) choice of network type to compliment what you already have established in your networks here..

It looks like to me ( so far), this should have the intended effect to balance out traffic a bit , between the various networks that have to handle a larger volume of traffic between 2 large cities.., with the added help from the expansive subway system,
But i also realize there are still phases of construction yet to be completed over in Arcens.. Before we are able to make a full assessment of the implemented changes you have completed and also that have yet to be planned here..

[pierreh]

I ran Marlande for some game months to activate the new subway link with Arcens. The results are encouraging, the traffic measured is already greater on the Marlande side, than it was on the Arcens side yesterday:



... But there is more work to perform, because the existing subway link to Desognes has become saturated:



In that case again, another subway link will be required. I have already determined where that new link will be placed, and I'll implement the change soon.


In a previous reply, Brian, you mentioned underground rail as a possible additional means of intercity transportation. My own experience with underground rail, several years ago, in one of my cities of the time, was rather dismal, I found it quite difficult to use, and therefore I have been neglecting it ever since. Btw, does it have an intercity connection?

[Darth-Apple]

I see you're running the new york city Subway... haha!

Very nicely done. I absolutely love the zoning layout you have as well. It's very well organized and a lot less scattered than all of my cities were.

[brian51]

Pierre,

i really like how the subway seems to be going for you so far.
It seems a very popular choice and it should help out with traffic overall considerably I think ..


Yes, it should be quite easy to put in a second tube , and I look forward to seeing a future update on this later my friend

In a previous reply, Brian, you mentioned underground rail as a possible additional means of intercity transportation. My own experience with underground rail, several years ago, in one of my cities of the time, was rather dismal, I found it quite difficult to use, and therefore I have been neglecting it ever since

Yes . i think it is rare I have ever used U- Rail in a later - scale way.. Mostly just to help out in a few small traffic situations where i had efw options to do anything else I think ..

Btw, does it have an intercity connection?

No, I am quite sure it does not have any intercity connections.. So you would have to go back above ground just before the border and use regular heavy rail  i think.

[pierreh]

Well, your latest comments about underground rail. Brian, convince me that its use is rather limited, and that it cannot really help much for intercity traffic.

Speaking of which... here is more about the Marlande-Desognes intercity traffic, where we saw in my previous post that the single subway link was saturated. A second link was implemented and put to use by running the cities. Here is the view of that new link from the Desognes side:



... and the surprise there - at least for me - is that the link is used for outgoing traffic! Sims residing in Desognes are going out, either to Marlande, or even to Arcens and further, to find work. I followed back to the origin of that outgoing flow: it comes from residences on the opposite side of the city! (Sims can't find work in their city of residence, and have to 'migrate' to other cities? Questionnable...)


Then I looked at the 'old' subway link, that had shown saturation on the Marlande side:



It is not, or no longer, saturated, although it remains close to the 64K limit. And there again, the flow is outgoing!

However, I only ran each of the 2 cities involved in this traffic for a few game months. It is a known fact that it can take a much longer time (a few game years at least) for the traffic simulator to adjust, stabilize and produce properly balanced flows and figures. Therefore I'll let some game time pass, before taking new measurements. Meanwhile I'll look at other issues in the global cluster.

EDIT, a while later

I ran Desognes for some more months. The 2 pictures above have to be discounted, they don't show the whole picture. Traffic on the subway links goes in both directions. I'll report about this later.

[SpookyZalost]

it's interesting you say that about underground rail, is that just a game limitation?

a couple real life examples that worked well for their time include the NYC Transit system which was originally an underground steam railway before becoming a subway system.
and the london underground.

it is true that a lot of places moved to electric tram/GLR/Subway type systems but I've always thought the idea of using full sized trains underground was kind of neat despite the obvious space issues.

so is that just a mod limitation, a game limitation, or is UGR just not very useful in dense urban landscapes?

looking at all this is making me want to maybe give SC4 another go... but I'm still waiting for flying cars

[Guardian]

it's interesting you say that about underground rail, is that just a game limitation?

I think its the game. I never had much success getting it to work as intended to help reduce congestion when I made the efforts many times years ago.