SimCity 4 Network Addon Mod by the NAM Team

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Note: The Traffic Plugins are also referred as Traffic Controllers, like other NAM files where only one file can be installed at a time.

Please remember only ONE of the NAM_Traffic_Plugin files must be installed at one time.  These are intended to replace the old NAM_Traffic_Plugins.  A Cleanitol file has been included to remove the old files.

What are NAM_Traffic_Plugins intended to do?

There are two central "cores" named A and B for lack of a better identifier.  These two central cores have both been mathematically designed to re-balance the structure of the Simulators.  With new information discovered by Mott from investigations he preformed the previous Simulators have been found to be harmful to the game in some cases.  Not only were the old NAM Simulators found to be flawed, but also the Vanilla Simulator from MAXIS was found to have flaws in it as well.  These two cores have been designed to limit and/or remove these flaws, as well as expand on ideas MAXIS had that simply were not implemented or not implemented properly.

What is the difference between Simulator "A" and Simulator "B"?

These Simulators have been designed to do two different things. 

Simulator "A" has been designed by JPlumbley to extend the original travel distances set by the MAXIS Simulators.  For example in the original game the MAXIS Simulator allows the Sims to walk up to 7 tiles, but with Simulator "A" the Sims will walk upto 43 tiles to get to work.  This change in travel distance is due to the calculations used to allow Car Traffic to travel one full distance of a large city tile (512 tiles) on Avenues. 

Simulator "B" has been designed by Mott to work with the original travel distances set by the MAXIS Simulator.  For example in the original game the MAXIS Simulator allows the Sims to walk up to 7 tiles, therefore in Simulator "B" the Sims will walk up to 7 tiles.  Simulator "B" has also been re-calculated to be more balanced and provide better pathfinding overall.

Other modifications to both Simulators include changes to the follow properties with minor variation:

  • Congestion to Accident Probability - Revamped the probability curve.
  • Congestion vs. Speed - Made use of this, not used to full potential by MAXIS.  Sims will now look for better routes if the network is over congested.
  • Trip Length to Minutes Display Multiplier - Used in calculations for time displays on Commute Time Graph.

What is the Park and Ride Mod?

The “Park and Ride Mod” is a mod that will make it so that cars cannot reach their destination.  So, what this forces you to do is place parking lots near transit systems, or in you CBD so that Sims can park and then walk or ride the rest of the way to work.  These are the Simulators named with a P after the Simulator Type like so:

NAM_Traffic_Plugin_AP_Easy

What do the different difficulties mean?

The only difference between the different difficulties is the Capacity of the networks.  All have been altered from the original MAXIS Simulator.  Road, OneWay Road and Avenue have all been equalized in speed and capacity in preparation for the Network Widening Mod.  The following is a list of the Network Capacities for each difficulty:

Network Easy Difficulty Medium Difficulty Hard Difficulty
Street: 2250 1500 1000
Road / OWR / Avenue: 5600 3750 2500
Highway / El-Highway:  10800 7200 4800
Rural Highway:  10800 7200 4800
Subway / El-Rail / GLR: 13500 9000 6000
Monorail: 13500 9000 6000
Rail:  13500 9000 6000

Note: The Easy Simulator was used during testing and was able to perform with astonishing results in a Medium City Tile with 1.8 Million Sims and counting.

What effect will the different difficulties have on my play style?

The Simulators are designed to help your game calculate proper pathfinding situations for your Sims to find their way to work.  Now, the Network Capacities have an almost equally important role in the way the Simulator works as the Maximum Commute Time and the Speed.  Some people will say that Capacity isn’t important and can be set to anything.  Well this is only a half truth, while Capacity "can" be set to any setting it is not wise to set the Capacities too high.  If the Capacities are too high the Sims will never look for another route beyond the shortest path because your networks will never become congested.  If the networks are never congested no speed will be lost and Sims will only take the shortest physical route.

Now, if the Capacity settings are set appropriately the pathfinding will act more realistic.  In Real Life roads become over crowded and then people look for other routes or new roads are built.  Having lower capacities will force you to design your networks more dynamically, plan ahead and provide more of a challenge.  But, if the Capacities are set too low, it will make the game too hard from a transit standpoint and prevent large cities.  If you have CAM, and a network capacity is set too low, one building may cause over congestion on any network if you are at some of the higher stage levels.

It is advisable that you choose your difficulty based on the size of the city you are planning to build or what stage you are in building your city.  Some general findings during testing find that for existing cities the Difficulties best perform at:

  • Hard Difficulty for cities up to 250,000 population.
  • Medium Difficulty for cities 200,000 population to 1,000,000 population.
  • Easy Difficulty for cities 750,000 population and greater.

Note: These are not set population values just estimates on where they should best perform at.

Of course there are differences for existing city sizes.  If you are starting a city from scratch, it is advisable to start on Hard Difficulty because it will allow you to build a city with a very well optimized traffic system.  If the city becomes too large your Simulator may benefit you moving down to Medium Difficulty.  But if you design your network from the beginning to be optimized for Hard Difficulty, you may never need to get to Easy Difficulty.

What are the Traffic Plugins "C", "D" and "E"?

Some of the old NAM Traffic Plugins have been renamed according to the new naming scheme and were included along with the new plugins that are listed above. These include the files with standard Maxis values, as well as the "Better Pathfinding" and "Perfect Pathfinding" plugins that don't change the speeds or commute times.

  • NetworkAddonMod_Traffic_Plugin_C_Standard.dat
  • NetworkAddonMod_Traffic_Plugin_C_Standard_2xCapacity.dat
  • NetworkAddonMod_Traffic_Plugin_C_Standard_5xCapacity.dat
  • NetworkAddonMod_Traffic_Plugin_D_BetterPathfinding.dat
  • NetworkAddonMod_Traffic_Plugin_D_BetterPathfinding_2xCapacity.dat
  • NetworkAddonMod_Traffic_Plugin_D_BetterPathfinding_5xCapacity.dat
  • NetworkAddonMod_Traffic_Plugin_E_PerfectPathfinding.dat
  • NetworkAddonMod_Traffic_Plugin_E_PerfectPathfinding_2xCapacity.dat
  • NetworkAddonMod_Traffic_Plugin_E_PerfectPathfinding_5xCapacity.dat

The “…_Traffic_Plugin_...” files in the Traffic Plugin folder have a naming scheme according to the following below:

  • "..._Standard_..." = The Standard Maxis values.
  • ..._BetterPathfinding_...” = A balanced Pathfinding: 0.0465
  • ..._PerfectPathfinding_...” = Accurate Pathfinding to the Maximum: 0.003
  • …_2xCapacity_...” = Standard Capacity values x 2.
  • …_5xCapacity_...” = Standard Capacity values x 5.

Notes

The file names explain what files contain what changes and are all based on the “…_Standard” file. If a file name contains two [or more] of the above names, then that means it contains those changes as detailed above.

A lower Pathfinding Heuristic value means more strain on your computer [i.e. go slower], especially with bigger cities and more traffic; longer times between cycles/updates, but it means a more accurate Pathfinding for travelling Sims.

With any of the “..Traffic..” files; when you decide on one or if you change between files, be sure to let the game run for a while so that everything can be updated [I would recommend 12 game months at least] to make sure everything is updated.

Please note: If you intend to use the Wide RHW (RHW-6C, RHW-6S, RHW-8, RHW-10), you should use either the Traffic Plugins "A", "B" or "Z". They have been adjusted to ensure proper usage of the wide RHW variants.

What is Simulator "Z"?

Simulator Z is a new traffic simulator based on the work of JPlumbley and Mott, who wrote Simulators A and B, while also incorporating the results of additional research into the workings of the internal Maxis traffic simulator. One of the main areas of the work on Simulator Z involved increasing the efficiency of the pathfinder to close to its theoretical maximum, while also increasing the Sims' maximum commute time to be closer to real-world conditions. This allows a smoother distribution of traffic throughout the city, with typically less congestion. At the same time, the congestion that does exist is less likely to lead to abandonment due to commute time; Sims know that they occasionally have to sit through traffic jams, and are a bit more patient. Better pathfinding also means that Sims act much smarter about finding jobs and routes to them; this also results in less abandonment due to commute time. As in the real world, zones can be farther apart without causing problems; this is especially helpful when building existing cities to scale. Finally, running the pathfinder with near-optimum settings allows the simulator to run up to several times as fast as previous simulators.

The second major area of work on Simulator Z involved a more flexible distribution of traffic among the various travel types. In combination with the pathfinder upgrading, this allows buses to be counted toward traffic and congestion, just like all other vehicles. This is a significant change from all previous simulators, and it's an important point to remember when planning your transportation infrastructure. More flexible distribution of traffic also means that Simulator Z is much more dynamic about allowing Sims to choose their transportation. In cities with excellent highways and road capacity, car usage has been measured at over six times that of previous simulators. Yet for cities with less extensive road networks and reasonable mass transit, car usage is actually less than in previous simulators.

Other changes in Simulator Z include the following:

  • More realistic subway costs. Subways in Sim City are tremendously underpriced compared to the real world. The improvements to the pathfinder have made huge networks of subways less necessary, so the monthly cost for subway tiles has been quadrupled to add a little more realism.
  • More realistic air pollution due to traffic. Until now, the amount of air pollution emitted by traffic has been unchanged from the original game, where it was based on cities that had far less traffic capacity than that used by any of the current simulators. To keep the amount of air pollution emitted by traffic to a more realistic amount, the proportion of traffic air pollution to actual traffic has been lowered in Simulator Z. This lower proportion is linked to the Clean Air Act, so it is in effect only when the Clean Air Act is enabled.
  • More accurate numbers for the Commute Time Graph. Due to a bug in the game, it is impossible to get accurate Commute Time Graph numbers for all situations. However, Simulator Z has adjusted the scaling of this graph to provide reasonably accurate numbers for most situations.
  • Improved intersection effects. Despite the appearance of stoplights at intersections, Sims don't actually stop; they don't even slow down unless congestion is present around the intersection. Simulator Z provides much more congestion around heavily-traveled intersections, thereby doing a better job of simulating stop lights and stop signs.
  • Greater monorail usage. Due to a bug in the game, monorail usage is generally less than it should be, sometimes by quite a bit. Simulator Z compensates for this bug by raising monorail usage to appropriate levels.

There are Park and Ride versions of Simulator Z, which work identically to the Park and Ride versions of Simulators A and B.

What are the different versions of Simulator Z, and how are they used?

Simulator Z comes in four versions - Low, Medium, High, and Ultra. The name of the version refers to the network capacities in the simulator. The following is a list of the network capacities for each version of the simulator; all capacities are per tile:

Network Low Medium High Ultra
Street: 1000 1200 1600 2000
Road / OWR / Avenue: 2400 4000 6000 12000
Highway / El-Highway:  9000 15000 22500 45000
Rural Highway:  6000 10000 15000 30000
Subway / El-Rail / GLR: 10000 16000 30000 65200
Monorail: 10000 16000 30000 65200
Rail:  10000 16000 30000 65200

Which simulator version is appropriate for a particular city depends primarily on two things: the population of the city, and the amount of rapid transit (rails) available. Less capacity is needed for lower population cities, but less capacity is also required for cities with a lot of rapid transit. For example, a city of two million Sims has been run quite successfully using the Low capacity version of Simulator Z, but it had an extremely extensive subway system. So pick a simulator version based on these two factors; if it doesn't seem the right capacity, you can always switch it out for a different capacity version. Experience has shown that in large cities, the effects of such a switch may take up to five years to fully manifest. You can tell when things have stabilized by looking at the Traffic Volume Graph in the following way: First, let the game run until there is a sudden shift in traffic patterns. Sometimes, this may take over a year. Then run the game until you go at least a full year without any sudden change in traffic patterns. At that point, the transition to the new capacity simulator is complete.

Traffic Volume View by z (installed along with the "Z" Traffic Plugins)

This Traffic Volume View offers a number of improvements to the one included with the game. Rather than the seven shades of blue in the original, this version uses the full spectrum of color, including approximately 48 distinct color shades. The maximum volume shown for each travel type has been increased from a flat 1200 for all types in the originalTraffic Volume View to a value which is 300% of the capacity of the underlying network for the selected travel type. (Since only one commute period is shown at a time, this is one half of the standard network capacity, which is calculated for a full day.) The legend has been increased from five to nine entries, and each color in the legend is followed by the percentage of the underlying network capacity that that color represents, as well as the actual number of Sims represented by that percentage. When a travel type may have more than one underlying network (e.g., cars may travel on streets, roads, or highways), a subtext below the legend indicates which network is being referenced in the display.

The colors in the display have been arranged so that they are more concentrated at lower levels, in order to give finer granularity at lower volumes. Between volumes of 0% and 10%, colors change about every 1.5%. Between 10% and 130%, colors change about ever 5%. And between 130% and 300%, colors change about every 10%. Please note that while every attempt has been made to attain the greatest accuracy possible, all numbers are somewhat approximate. The numbers following each color in the legend refer to the approximate beginning of the range of that particular color.

You may notice that starting at 100%, the colors closely follow those in the Traffic Congestion View. However, it is important to keep in mind the difference between theTraffic Congestion View and the Traffic Volume View. The Congestion View is compiled from an entire day's travel statistics, while the Volume View refers to only a single commute period. Therefore, yellow in a single volume view does not necessarily indicate congestion, and blue or green in a single folume view does not necessarily indicate lack of congestion. Furthermore, some of the volume views include non-congestion producing travel types, which are pedestrians, buses, and ferries. An experienced player may be able to look at both commute periods of certain volume views and get a good idea of congestion, but it is necessary to be careful here.

Finally, most transit station types light up in all volume views. This does not indicate anything about usage; it is simply so you can identify them easily. Certain types of transit stations do not light up because of the way they were designed.

File Last Updated: Wednesday, 14 January 2009