Do ring roads really work in SC4?

[poshbakerloo 186]

Do ring roads really work in SC4?

A lot of my cities end up having inner loop motorways around downtown, but I find that the motorway will be dead and the road inside it very full of cars! I have the latest NAM aswell which is meant to fix a lot of pathing issues. I have got a lot of straight line bypasses to work, but never sure if making a full loop is of any use...

[TekindusT 3,809]

Short answer: NO.

Long answer: The NAM traffic simulation just changes the game's idea of "the shortest route is the good one" to "the less time-consuming route is the good one" (a NAMite will be able to go more in-depth with this). In both cases, the idea of "the less conngested route is the good one" is not considered, then, building ring roads in your cities will be unnecessary. In case you have the NAM installed, only short sections of your ring roads will be used for commuting, but you can forget the idea of Sims driving more than a couple of exits in a ring road.

In my experience, building a fantastic ring road system with 1, 2 and even 3 rings has been a complete waste of time and, in most of the cases, I've seen 0 commuters travelling on them while the city center gets more congested. Ring roads are very realistic as many major cities in the world have them, but they don't have the traffic simulation the game has.

[Haljackey 17,385]

Remember that SC4's traffic simulator only accounts for commutes from home to work and vice-versa. Recreational traffic is not accounted for. The only exceptions is freight truck traffic (which find the fastest way out of the city) and spawning vehicles from certain buildings (like a police station) that just drive around randomly until the vanish.

Thus planning a road network can be tricky if you want to maximize its use, especially when it comes to highways. You'll want to make them attractive for your sims by providing a direct, efficient connection that's faster than taking arterial streets.

There are certain mods that can help with this. Of course the NAM updates the traffic simulator to make it 'less dumb', but there are others as well. Some will help force sims to take the fastest method of commute, which usually involves highways since they move sims faster than roads.

[Vahr 343]

It all depends on your layout - my cities are laid out so that highways are the most preferential route taken by sims. Taking a surface road will often force a sim to wind back and forth and will often run into more congestion (which, ironically, is often caused by sims heading to the highway ramps to escape said congestion), which the simulator sees as undesirable.

[Magneto 316]

Interesting topic!

Well too bad this doesn't work in SC4 but it wont prevent me to do those ring roads anyways, I love them too much

[Ion_Cannon 677]

You can definitely force sims to use your major routes, wether those be highways or avenues. One way of doing it is to have only 1 connection from neighbourhood A to get onto route B, in a city of many such neighbourhoods don't connect the neighbourhoods together, block it either by way of natural obstacles or by using a transport line or a large factory so that it seems natural and not forced. Sims will then have to use route B to travel from neighbourhood A> factory area 1, office area 2 ect ect

You can also massively increase the efficiency of your networks by having as few intersections as possible, use either on/off ramps or roundabouts instead.

[NCGAIO 562]

The fact is that the theory does not always work for the simulation. Even if it's the perfect way, we always find things like this.

Although hundreds of jobs much closer. some will go more than forty sheets for it. Maybe like driving more than others!

And even standing next to employment will happen abandonment by long commute

Go figure ....

  Edited July 10, 2012 by NCGAIO  

[metasmurf 705]

As Ion_Cannon points out, you have to force your sims to use motorways by giving them no other alternative. You can still connect neighbourhoods visually by using traffic control lots (also known as traffic blockers).

[z1 566]

I just got the "You have posted more than the allowed number of quoted blocks of text" error. So please forgive me for breaking this up into two posts.

(a NAMite will be able to go more in-depth with this).

I guess that's me...

Long answer: The NAM traffic simulation just changes the game's idea of "the shortest route is the good one" to "the less time-consuming route is the good one"

Specifically, the NAM traffic simulator always chooses the least time-consuming route, where the time consumed may be affected slightly by the Sims' preferences for mass transit or driving. There is also a 24-second handicap for driving (which is a lot for an SC4 commute).

In both cases, the idea of "the less conngested route is the good one" is not considered, then, building ring roads in your cities will be unnecessary.

Congestion has a big effect on speed In all versions of the traffic simulator. If a road shows up as solid red in the Traffic Congestion Data View, then its speed is reduced to 30% of the network's nominal speed. This is taken into account, especially by the NAM traffic simulator, so the Sims generally do try to avoid congestion, at least with the NAM.

In case you have the NAM installed, only short sections of your ring roads will be used for commuting, but you can forget the idea of Sims driving more than a couple of exits in a ring road.

This is generally true regardless of which traffic simulator you have installed. Commutes in SC4 are much shorter than those in RL; they're usually no more than about six minutes. This is why certain RL traffic patterns (such as using large portions of a ring road in a single commute) generally don't show up in SC4.

Chances of ring roads (and highways in general) being used in SC4 are much higher with the NAM traffic simulator, not only due to the fact that the perfect pathfinding allows the fastest route to be found, but also because highway speeds are much faster. (Road speeds are faster too, but the net effect still favors highways significantly.)

Remember that SC4's traffic simulator only accounts for commutes from home to work and vice-versa. Recreational traffic is not accounted for. The only exceptions is freight truck traffic (which find the fastest way out of the city) and spawning vehicles from certain buildings (like a police station) that just drive around randomly until the vanish.

Although freight traffic (both truck and rail) is accounted for by the traffic simulator, spawned vehicles appear only on the automata level, and do not affect the overall traffic simulation.

Thus planning a road network can be tricky if you want to maximize its use, especially when it comes to highways. You'll want to make them attractive for your sims by providing a direct, efficient connection that's faster than taking arterial streets.

Basically, the key to making sure highways get used is to place them along or near routes that the Sims want to travel.

There are certain mods that can help with this. Of course the NAM updates the traffic simulator to make it 'less dumb', but there are others as well. Some will help force sims to take the fastest method of commute, which usually involves highways since they move sims faster than roads.

The NAM traffic simulator does all of this; no other mods are necessary. To the contrary, other mods may interfere with the ability of the NAM traffic simulator to find the fastest route.

Of course there's the Traffic Simulator Configuration Tool, but that's just a tool for modifying the NAM traffic simulator - I wouldn't call it a mod in its own right.

You can also massively increase the efficiency of your networks by having as few intersections as possible, use either on/off ramps or roundabouts instead.

Actually, despite what some documentation says, intersections have almost no effect on traffic flow. Most intersections have no effect whatsoever; the Sims just drive through them without even slowing down. This includes most intersections that have stoplights; what the automata do does not correspond to what's really happening with the traffic. The only time there's even a slight slowdown at intersections is when they show up as yellow or red in the Traffic Congestion Data View. Even so, this almost never makes enough of a difference to have an effect on the routes that Sims choose.

  Edited July 11, 2012 by z1  

[z1 566]

The fact is that the theory does not always work for the simulation. Even if it's the perfect way, we always find things like this.

Although hundreds of jobs much closer. some will go more than forty sheets for it. Maybe like driving more than others!

Are you using the NAM? Even if you are, remember that workers and jobs must match up not only by wealth level, but also by education level. Also, it's not possible to have all Sims travel to the job closest to them, nor does the traffic simulator try to accomplish this. Instead, the destination finder (which runs as the first part of the traffic simulator) looks for suitable jobs for the Sims, without going into all the details of the pathfinding process. So jobs may be far away (I've seen Sims travel from one corner to the diagonally opposite corner on a large map), but if Sims can reach them, there's not a problem.

And even standing next to employment will happen abandonment by long commute

If the NAM traffic simulator is being used, then this typically happens if the Sims don't have the qualifications for the jobs next to them, or if the desirability of the jobs or residences is too low.

As Ion_Cannon points out, you have to force your sims to use motorways by giving them no other alternative. You can still connect neighbourhoods visually by using traffic control lots (also known as traffic blockers).

This is a little bit of overkill. All you have to do is to ensure that the motorways are part of the fastest route from the Sims' residences to their jobs. (Note that in the evening commute, the "fastest" requirement is not applied by the game.)

[metasmurf 705]

This is a little bit of overkill. All you have to do is to ensure that the motorways are part of the fastest route from the Sims' residences to their jobs. (Note that in the evening commute, the "fastest" requirement is not applied by the game.)

Sure, but this means motorways have to be layed out in an unrealistic and problematic manner, i.e straight from sims homes to their workplace. This also means that you have to make room for motorway intersections in, for example a downtown area or port where it might not be suitable in terms of space and looks.

  Edited July 11, 2012 by metasmurf  

[z1 566]

Not at all. Since highways are so much faster than roads, Sims will go out of their way by a reasonable amount to use them, at least if you're using the NAM traffic simulator.

One example of this is in my Chicago simulation, where Lakeshore Drive is separated from the rest of the city by Lincoln Park. During this stretch, there are no businesses or residences adjoining it. Yet the Sims use it a lot, because it's so much faster than the city streets.

[Darkwings 5]

I have that sort of highway-ring all around a city nearby (I mean in real life) and I'm using it in game, with good results. (with NAM of course)

Sims will go for the faster route, they won't congest my R center and having 2-3 exits around the C center ensure the desired amount of congestion.

The same goes for sims that want to go in/out of town, since the ring is connected to the border.

Of course any 'foreigner' is forced to enter from the C district, for obvious reasons.

For any traveler who want to just bolt through the city, a bypass (usually an underground one) is there to grant them a direct route (since they're not stopping in town, there's not much point in increasing congestion on both ends).

[NCGAIO 562]

Are you using the NAM? Even if you are, remember that workers and jobs must match up not only by wealth level, but also by education level.

This is under the NAM 30 and bugfix. The lack of lanes if what was observed on the roads is the result of applying one-ways for controlled tests.In the case mentioned lots zoned with same wealth, same creation date then presumably have the same education ..

Also, it's not possible to have all Sims travel to the job closest to them, nor does the traffic simulator try to accomplish this. Instead, the destination finder (which runs as the first part of the traffic simulator) looks for suitable jobs for the Sims, without going into all the details of the pathfinding process. So jobs may be far away (I've seen Sims travel from one corner to the diagonally opposite corner on a large map), but if Sims can reach them, there's not a problem.

It was exactly what I meant about the topic and more specifically as you explained in detail sometimes can not say that "Specifically, the NAM traffic simulator always chooses the least time-consuming route" taken by many as just driving to work closest .

And in my observation, how higher the city ( higher the traffic of course) greater the amount of deviation "destination finder" coming to all cases of work of a lot being in this situation.

If the NAM traffic simulator is being used, then this typically happens if the Sims don't have the qualifications for the jobs next to them, or if the desirability of the jobs or residences is too low.

Sorry the picture does not fit .... I refer to industrial plant the right tile test (Somy modified) ... lots R$ just below it show Abandon Comute after that route was changed to the other. In this particular case had been working in the industry so there was no change in both qualifying and the desirability. Simply the simulator did not find new jobs so to speak!

Anyway nothing is perfect.

  Edited July 12, 2012 by NCGAIO  

[packerfan386 3]

Does this count?

The actual morning commute from one of my suburban subdivisions.

  Edited July 12, 2012 by packerfan386  

[Jimmy Buzaid 53]

Oh my god. One time 80 sims in another city came in and all the way across another city just so they could take the train back into their city.

[A Nonny Moose 8,262]

Oh my god. One time 80 sims in another city came in and all the way across another city just so they could take the train back into their city.

That, my lad, is a pernicious commuter loop.

[Moskva 75]

My ring roads do work. Lenin'sk city core is surrounded by a big avenue ring, which is used. For example, someone living on the ring road has to go on the opposite side of the ring, wont cut the city but will use the ring, usually... However, try to make "freeway rings". Like others said, NAM has changed the traffic simulator, people now seek for faster route, no more shortest one. So freeway rings would do fine!

[NCGAIO 562]

Does this count?

The actual morning commute from one of my suburban subdivisions.

Another good example!

Out of curiosity, if you still have the city remove the building job and let the game run for a year and then see where the sim was relocated.

[jorgedasilva 0]

It works for me. I've built 5 ring roads which are motorways and 4 which are Dual Carriageways

[A Nonny Moose 8,262]

A little adroit setup should make ring roads work.  If you don't have any cross-town main arteries, they will be the fastest routes and the Sims will use them.  It's all in how you connect your pods.

[Cob92 360]

You just have to make sure that they follow existing commute patterns, and that they aren't so long that the advantage of extra speed is negated by the distance. I can think of at least one real life example of a ring road that has mostly failed to get the hoped-for usage; the 130 around Austin was built to alleviate traffic on I-35 in the urban core, but because the 130 was built so far out to the east of the developed parts of the city, it gets little usage outside of traffic bound for San Antonio (proposals have emerged to toll the original 35 and force traffic to reroute to the ring road). Houston's ring roads took some time to get high usage as well, with the rise of congestion on Beltway 8 following the growth of suburban sprawl and secondary employment centers along it. It's generally used for suburb to suburb commuting or as a bypass to get around the far worse traffic in Houston proper.

[ZeusAV 20]

Yes with the NAM installed the Sims more certainly can and will use your ring roads and freeway bypasses.  I'm a highway guy and much of the enjoyment I get out of this game is from designing the transportation networks.

 

Some things I've found to work:

 

- Whatever city that you have your ring in or your bypass, you need to have neighboring cities.  This makes it so that your sims actually have some reason to use your bypass.  If there's no significantly sized neighbor in the adjacent or 2 tiles away then they won't use them.

- Cutback on your neighbor connections.  When using freeways I design my cities so that those are the best and sometimes the only way to get to a neighboring city. Since the NAM makes sims use the fastest route instead of the shortest, this also helps get more traffic onto your highways.

- Keep your design realistic.  Take a look at Google Maps and observe how some real world cities have their highway grids laid out.

 

Here are a couple examples of how I did mine. The first city 'Amherst' has a very large neighbor to the right of over 1 million, a 20k neighbor to the left and small 5k neighbors to the north and south.

 

The second one 'Kileen' has a very small 3K neighbor to the north where the highway leaves the screen, the neighbor to the south is around 30k.  Interesting thing with this one is that the sims are traveling through the 3k neighbor to the north where I have another bypass and into a 300k city 2 tiles away. Notice the 3rd city has a full ring and about 600K sims. Notice that the northwest portion is the least utilized part. That's mainly because the neighbor to the northwest is a small farm town of only about 3K.