[brian51]

Pierre,

thanks so much for your latest CJ update !

Oddly enough I think I also have 1 city where the CAM Fix seems to do what it is supposed to do.
Of course I have no explanation as to why its just that 1 city ?

But yes, I think the right thing to do is simply ignore this large ( Blue) commercial demand also once we
feel we have plenty of commercial jobs for the sim population we have..

If I can find this city with the lower commercial demand , I will post an image or screen here in your CJ..

[pierreh]

Meanwhile a second city in the Talaran cluster has reached a population of 1.5 Mio SIms:



And I am not reporting, at this time, the traffic issues I have in the cluster, with inter-city travel getting entirely out of hand.

Due to some testing activities in the realm of NAM, updates to this CJ may be less frequent for a while.

[brian51]

Congrats on this Pierre !

You are now starting to close in on my region population record

[pierreh]

I have a rather unsettling event occuring in one of the Talaran cities, namely Marlande: in the span of a few game months, there has been large-scale abandonment of residential buildings in an area of the city, with the note about excessive commuting time, and a loss of population of about 25'000 Sims. To a lesser degree there is also abandonment of some commercial buildings, on the ground of insufficient attractivity.

It is the first time this is happening in the cluster, where otherwise cities continue to grow, albeit at a slower pace now that they have reached a rather mature stage. It is, therefore, quite surprising.

I'll be researching the possible cause of this. A priori I can only suspect that some networks are congested, preventing the Sims to commute from home to work (and back, but the evening commute plays a much lesser role, if any, in computing travel time).

[brian51]

Yes, i think maybe try working on traffic of course, but also try more trees and park s near the abandoned areas.
This usually works quite well for me .

[pierreh]

Thanks for your reply, Brian. As far as trees and parks go, I don't think that I can place more of those in the areas where I get abandonment: since I do not like empty tiles, I tend to fill all little angles, corners, etc, where it is not appropriate to zone buildings, by parks, fountains, trees, etc. But the advice is still very adequate, and I'll review the affected areas.

Meanwhile, since I don't only have problems (mostly with traffic) in my cities, I'll show a few pictures of parts of them where I am rather pleased with what is in place. As I had noted very early in this CJ, I am not hung up on 'eye candy', my main focus is traffic, transportation networks and in the present case the effects of region playing. Still, I try to make the cities looking nice without spending an excessive amount of time for it.

I'll start with a highway interchange in the midst of Cherenne. I am not a great specialist of RHW, but in the particular case I managed to build a rather tight, fairly symmetrical, and fully functional, T-interchange, and to stich up the city around it, commercial zone on the right, residential zone on the left:

[pierreh]

A new milestone has been achieved:



Then, the next milestone, in terms of region population is, of course, 18 Mio Sims.

-----

Two pictures taken in Deramey (Talaran cluster). The first one is a view of a major crossing of avenues on the north shore of the central business district. The statue in the center of the traffic circle is that of Auguste-Hyppolite de Labarre, Count of Deramey, founder of the city and its first mayor.



The second one shows the Peninsula, at the junction of the two major waterways that run thru Deramey, necessitating many bridges for the various networks; 3 of those bridges can be seen in the picture.

[Darth-Apple]

Beautiful! Love the bridges that go across and enter into roundabouts and diverge from there. Very nice work indeed.

[brian51]

yes, I agree in the beauty of these cities.

And so there are now 2 new goals on the horizon for you, Pierre

First as you mention the 18 million
and than secondly, my current region population is around 18.2 million

[pierreh]

Today I have good news and not so good news.

First the good news: the strange abandonment of residences, and to a lesser degree of commercial buildings, in Marlande, about which I reported recently, has ceased. In the last playing sessions of that city, residents have returned, to the point that the current number of inhabitants in that city is higher than ever before. I didn't do anything to cause either the abandonment, or its reversal, I let the city 'play itself', with no intervention, other than monitoring and fixing subways (see below). Of course I am not the wiser, as to why the abandonment happened, and why it ceased. For the moment I'll consider it as a fluke in the game play. If it occurs again I'll try to look into things in more detail.

Now for the less good news. It has to do, to no-one's surprise, with regional playing and inter-city traffic between 2 cities: one of these cities is Marlande, the 'abandonment city'; the other is Desognes. I think that I have already mentioned in this CJ (a long time ago) that I am using the 'Ultra-Euro-Custom' version of the traffic simulator. )n the famous tutorial "Understanding the Traffic Simulator", we find the following note about subways:

"In deciding whether a job is reachable from a residence with the current traffic simulator settings, the destination finder weighs the presence of subways very heavily, especially subways that go very near the residence, and presumably, those that go near the job as well."

And about mass transit in general, the tutorial contains: "Perfect pathfinding results in much higher mass transit usage, which means less road traffic in general.". 'Perfect pathfinding' is defined in detail in the tutorial; the value of the Pathfinding heuristic property that produces perfect pathfinding is 0.005797. That value is used in the simulator I am using.

As already documented, I implemented, in a gradual fashion, inter-city subway links between the cities in my clusters. In the particular case of the inter-city traffic between Marlande and Desognes, there are at present no less than 11 inter-city subway lines (one of which being in fact a line that passes thru Marlande to reach Arcens).

What I'll document here, and what bothers me a lot, is the discrepancy between the number of travelers in the subways, reported at the respective city borders. I'll show here the 11 inter-city lines, seen in both cities, with the numbers shown in the traffic queries. Desognes in on the left, Marlande is on the right:

For the 2 lines above, Marlande reports over 60% more travellers.

For the 4 lines above the differences are less than before, but the numbers reported in Marlande are systematically higher than those reported in Desognes. The 'highest' line in the picture is saturated in Marlande.

For the 2 lines above, Marlande reports 2.2 times, respectively 3.3 times more travelers than are measured in Desognes.

Finally, for the last 3 lines, the discrepancies are even greater: two lines that show modest traffic in Desognes are both saturated (!) in Marlande, and for the 3rd line it is the reverse: that line is saturated on the Desognes side, but not on the Marlande one - in fact, this is the only line where Marlande reports less than Desognes. It is also the 'pass-thru' line to Arcens.

I never expect that numbers will jive exactly, since cities can't be played simultaneously - there is always a delay effect. But in my previous observations the differences between both sides of an inter-city subway link were rather minor, on the order of a few percentage points. Here we have major discrepancies.

Well, I must live with that, since I intend to forge ahead with the development of the cluster. I'll concentrate presently on the situation in Marlande, where the highest numbers and most saturations are found. I need to determine where Sims reside and where they work in the other city (traffic goes both ways), rearrange the lines, possibly dismantle 'weak' lines, beef up where there is saturation, and so on. That work has already started, but since it involves additional links to the neighbor cities, I’ll have to play those to get the inter-city traffic to adjust itself. Plenty of work to keep me busy....

[brian51]

Of course I am not the wiser, as to why the abandonment happened, and why it ceased. For the moment I'll consider it as a fluke in the game play. If it occurs again I'll try to look into things in more detail.

I always felt there are also cyclical recessions that vary in strength in the game
So maybe this is at least part of the reason ?

I never expect that numbers will jive exactly, since cities can't be played simultaneously - there is always a delay effect. But in my previous observations the differences between both sides of an inter-city subway link were rather minor, on the order of a few percentage points. Here we have major discrepancies.

Well, I must live with that, since I intend to forge ahead with the development of the cluster.

Yes, we have always known here are some traffic bugs in the city connectors.
Either this is in the traffic reporting or the actual traffic, or both .

I do have one suggestion though that may or may not help.
I have heard it makes things more difficult and less accurate if you have crossing networks that are near the edge of the map , where the city connectors are. So in marlande, you have that one crossing subway tube fairly close to the edge of the city border there. If there was some way you could move that a  few more tiles further away from the border, I would be curious if this helps balance the traffic more ?

[pierreh]

So in marlande, you have that one crossing subway tube fairly close to the edge of the city border there. If there was some way you could move that a  few more tiles further away from the border, I would be curious if this helps balance the traffic more ?

Actually, that subway crossing was a mistake. In my 'doctrine' about subways, such crossings are an absolute no-no - I explained why in my long 'subway rant' quite a while ago in this CJ. Here is an enlarged view of it:



This has meanwhile been corrected. I rerouted the east-west subway tube, to remove the crossing. The new routing is shown in this picture; the old route is represented by a dotted red line:



The new route for the subway line, and the other line to which it runs in parallel to Desognes, cross a GLR at the station, so there should be no adverse effect of that crossing. The new route doesn't carry any traffic yet, because it is not yet connected on the other side, in Desognes. This will be done the next time I play Desognes. Since I play my cities in round-robin fashion, I'll get back to Desognes later, and to Marlande too. I expect to deal further with the inter-city traffic in various ways.

[brian51]

Pierre.

thanks for the update here !

Yes, let us see what happens( with the consistency of the inter -city traffic values),.. when you start playing the cities some with your new set up.

You really have some interesting topics going on right now in your CJ

[pierreh]

More about inter-city traffic today, and especially about pass-thru traffic.

I already documented in this CJ the use of simple pass-thru subway lines. In the mean time I have implemented more of those. Here is a typical example, in Polsay: the subway line links Arcens and Salveille, with no station in Polsay:



In that case, the work of the traffic simulator is quite simple: what it finds arriving at one extremity of the subway tunnel, it has to move to the other extremity - what comes in, must go out, in both directions.

The story becomes much more interesting with highways, when there are ramps in the city in the middle, where cars, buses and trucks can enter and exit the highway. The traffic simulator should have a lot more choices with traffic incoming from an inter-city link.

A RHW-8S highway links Salveille and Polsay. In the morning, the traffic is very predominantly from Salveille to Polsay:



Summing up the numbers given by the 2 queries we obtain: 20'509 cars, 1683 'buses' (= Sims traveling on buses) and 5435 trucks. The highway is quite well used.

Looking on the Polsay side of the highway inter-city link, we see:



Measurements give 20'659 cars, 1516 'buses' and 10 trucks (actually, at the exact city limit the number of trucks is likely 0, and the 10 trucks are fed to the highway by the industries bordering the highway; at any rate, there is no such thing as inter-city truck traffic). The numbers for cars and buses are reasonably close to those measured in Salveille.

Now, Sims coming from Salveille in cars and buses are looking for jobs in Polsay, and there are ramps allowing to exit the highway into the city. Do they find them? Apparently only a minority of those Sims do find work in Polsay, the majority of them stay on the highway that goes thru Polsay and links to Arcens. Here are the stats taken on the highway near the connection to Arcens; it has become a RHW-6S:



Of the 18'946 Sims in cars going to Arcens, there is quite likely a small number that resides in Polsay, but the majority of those Sims come from Salveille. And the enlarged traffic map for Polsay shows that the highway is busy (red) all the way thru that city:



Now the plot thickens: one would expect that those Sims who couldn't find jobs in Polsay, would then find jobs in the next city, Arcens. This is probably true for a minority of them, but the majority drives thru Arcens to the next city, Deramey! Again, there are ramps in Arcens allowing exit from and entry into the highway. On the Arcens side of the highway link we see:



There are 18'849 cars - very close to what the query on the Polsay side shows (we ignore the 'buses', because of the small numbers, athough the reasoning probably also apply to those). At the inter-city link to Deramey we have:

 

We see 18'651 cars - again, very close to the previous measurement. And the traffic map for Arcens shows clearly that the highway (circling a part of the downtown area) is busy from end to end:



What happens in the next city, Deramey? Do the Sims finally find jobs there, or do they, poor souls, have to forge on the next, and final city, Cherenne? This will be examined in a later post.

But already, this leads to wondering about the traffic simulator's 'tactics': it would seem that, given the choice between finding jobs for Sims in a city that has a highway passing thru it, and letting the Sims driving their cars remain on the highway to the next city, the simulator favors having most of the Sims stay in their cars and drive thru. The destination finder part of the simulator considers the next city to be closer that any commercial or industrial location in the city - which is probably true in most cases. The simulator works according to the rules documented; the actual effects on the intra- and inter-city traffic are rather interesting.

[brian51]

Yes things seem to be going better in terms of more balance traffic numbers that use the connectors between cities.
The numbers look to be very close there.

But yes, I have to agree that the most exciting aspect on this update would have to be the number of sims are willing to drive thru multiple
tiles to find jobs !

[pierreh]

A bit of highway improvement today.

In the city of Deliambert (Sambey cluster), the end of the highway was constructed at an early stage of developement, with a very limited understanding of all the possibilities of RHW, and also possibly a limited amount of options in NAM at the time. The result was a rather poorly designed exit ramp with two sharp 45 degree curves that gave headaches to drivers, generated traffic jams and were the cause of multiple accidents (especially because many drivers ignored the speed limit imposed by the geometry of the roadway). It looked like this:



After many years of fruitless discussions in the municipal council and its transportation commission, a budget was finally voted for the reconstruction of the exit ramp. The plans had been ready for quite a while, and the work required was expedited swiftly by a local consortium of public work enterprises. The new ramp was inaugurated in the past few days, and is shown here:



In a later post I'll illustrate a quite larger reconstruction project for a highway interchange in Arcens.

[Guardian]

That looks great!

[brian51]

oh Pierre,

I really like this new posting and your upgrade here.
You are starting now to improve rapidly in your use of the available content to improve your highways systems
This is one of the more impressive improvements you have shown in Deliambert .