Let me take a moment to tell you about my Cities Skylines playstyle. At first I was a die-hard vanilla guy, sticking with the progression system and trying to hammer out some basic cities that simply *worked* without getting totally clogged up, or look like a Pollock painting, or a cartesian plane.

Over time, as I became more comfortable with the game mechanics, particularly regarding what things are needed and when, I began experimenting with the workshop which offers a wealth of wonderful player-created assets. As I got the hang of things, started looking at pictures of glorious user-created cities and watching youtubes of phenomenal, beautiful, intricately detailed cities, my experimentation caused me to arrive at the conclusion that imposing these optional boundaries on myself was only limiting my capabilities.

Today when I play Cities, my goal is to create the most attractive, succesful, "ultimate" cities I possibly can, applying best practices to my city planning, layout, and decor. With that said, this guide does not cater to the min/maxers or the completionists. We will not go over how to set district policy or make piles of money. This is for the aesethetes, the perfectionists, and the dreamers. If you want to build a functional, beautiful, realistic city, you have come to the right place.

DLC

The following is my list of must-have DLC's to maximize your creative city-building mojo. These add indispensable content and enable you to utilize virtually any user-created content.

• Mass Transit. Ferries, monorails, cable cars, and blimps. Blimps that educate your citizens on the necessity of brushing their teeth. Excellent.
  
• After Dark. Much more entertaining and lovlier day/nite cycle. Great service assets (cargo harbors, international airport).
  
• Snowfall. Trams. 'Nuff said.

Mods

The following mods are must-haves in my opinion, although they are roughly in order of importance. Even if you do not pile on a million beautification assets, these make the game far more user-friendly, enjoyable, and lovely.

• Precision Engineering. Extra tools to help you lay out your roads. Specify if a road is to follow the ground, use elevated roads, etc.
  
• Move It!. Will not only save you ages building nice intersections--will also allow you to make realistic road curvatures that are otherwise unattainable in vanilla.
  
• Extra Landscaping Tools. Terraforming. Make land level so you dont have weird divots everywhere.
  
• 81 Tiles. Build anywhere on the map. Grants you complete freedom to build wherever on a whim.
  
• Network Extensions 2. Additional super nice and practical road options (e.g. the 8 lane road gives a bridge model like the Bunker Hill Memorial Bridge [BOSTON STRONK!]).
  
• Quay Anarchy. Quays are supremely useful for quick and easily assembled inner city/harbor coastlines as well as barriers for sunken construction. Put them all over the place easily.
  
• Surface Painter. Perfect to clean up things like pesky dirty/odd looking spaces like those between turning lanes (thanks asphalt paint).
  
• More Beautification. Allows you to place props--nice little accent pieces like walls, signs, benches, etc.
  
• Prop and Tree Anarchy. Easily make high-density forrested areas.
  
• Loading Screen Mod. Supposedly speeds up game loading progress; a must-have for low-RAM (8 GB or less) users. See how long it takes to load your city and what mods are broken.
  
• Traffic Manager President Edition. Manually arrange the lanes used by sims and a million other traffic control options.
  
• Prop Line Tool. Make lots of props fast and orderly, essentially using road tools.
  
• Dynamic Resolution. immediately make your crappy city look super duper pretty.

I have prepared a full mod collection for those of you who want a no-brainer, one-click option for all the most important mods that I believe will offer you the best possible cities skylines experience. The collection can be found here:

http://steamproxy.net/sharedfiles/filedetails/?id=1279401265

Keep in mind that you may not want all these mods active at all times (example, Super Demand mod if you want to play with vanilla zone demand) so you may want to at least review them, and enable on-off in the in-game content manager if you are ready/not ready to use.

How to Mod without Breaking your Game

Its easy to go crazy and download everything on the workshop. This can result in breaking your game. Here are some times to prevent this.

• Create dedicated collections to organize large numbers of assets. Example, "*insert your name*'s CS Service Buildings." This will help you keep track and cut down if necessary.
  
• Only choose assets that are low file size. Some trees, buildings, and packs can eat 25-100 mb! Do not download these. Max size recommendations: props shouldnt be more that 1-3 Mb, trees 1-5 mb, buildings 1-10 mb for most.
  
• If you really like an asset but you don't expect to use it frequently, "favorite" the item instead of downloading it.

To Cheat or Not to Cheat?

Verb.

1. act dishonestly or unfairly in order to gain an advantage, especially in a game or examination.
"she always cheats at cards."
2. avoid (something undesirable) by luck or skill.

Now that you know what motivates me about Cities Skylines, you may have an idea how I feel about "cheating." While the vanilla, standard unlock progression game I will certainly recommend to beginners still learning the basics mechanics, I encourage the more experienced among you to cast aside these shackles so you can take your Skylining to the next level.

By the above, there is no "cheating" in Cities--this is a singleplayer game that I believe should be played in a manner that suits your motivations. If you are like me (and any of the talented youtubers out there putting out Cities content), then the usual restrictions need to be eliminated to get to the next level.

Enable the following:

• Unlimited Money. In real life I reckon you get more than 70k to found a flipping city. Seriously, especially with all the trial and error that goes into design that you can't otherwise plan in advance, you will need the money.
  
• Unlimited Soil. Terraforming will play a big role in creating idyllic cities. Don't let the game's restrictions stop you.
  
• Unlock All. If you know what you are doing and have freed yourself from the burden of financial restriction, there is no reason to keep to the progression system. You will want to carefully place your most important services and buildings earlier than the game will otherwise allow it.

The following is a description of terms used in this guide.

Access Road. A minor road type that gives access from one major road type to another.

Arterial Road. high-capacity road type that usually comprise dedicated 2+ lane one-ways running parallel. Roads that the game provides when you start a map are arterial roads. These roads connect towns/large districts/cities. Use anything from two to six lanes per one-way (the latter being overkill really; if you think you need them then you're probably doing it wrong).

Arterial roads have very few entry/exit points and should not have entry points closely in advance of exit points as this results in weaving, a situation in which outgoing traffic conflicts with oncoming traffic.

Collector Road. a low-to-moderate-capacity road type which serves to move traffic between local streets and arterial roads. These roads always connect to an arterial road at some point and link districts. These minimally use four lane and six-lane roads in high-density areas but two lane roads can be fine in lower-density areas. You can use one-ways for these, too, but intersections can get tricky. Unlike arterials, collector roads are designed to provide access to residential properties.

Collector roads should not have many intersections. Place service buildings on these roads to maximize area of effect (AOE). Zone commercial areas on collector roads.

Freeways. High-speed limited access express roads that are not obstructed by junctions that require traffic to come to a stop. This is critical to their function. Arteries are freeways. May be parallel one ways or two-way roads. Any road can be a "freeway" really if you connect it to other roads with highway ramps.

Frontage Road. A low to mid-capacity road allowing the placement of several access roads to a collector or arterial road in close proximity while minimizing the number of access points to the artery, minimizing interruption of transit on said road.

Grade Separation. aligning a junction of two or more roads at different heights (grades) so that they will not disrupt traffic flow when they cross each other. See Step 4 first image for an example.

Highway. A road with long stretches that are without any intersections but may be accessed wihtout ramps and may have to come to a stop (stoplights). Highways typically have lower speed limits and may pass through inhabited areas where there are traffic signals, pedestrians or other slower traffic. Collector roads can double as highways. Please note I do ocassionally refer to a freeway as a highway colloquially.

Interchange vs. Intersection. There is an important distinction to be made here. Interchanges connect collector and arterial roads in a free-flowing manner where traffic is redirected to a new direction by ramps or slip lanes without stopping (no traffic lights) and at high speed, while intersections connect low-speed local and collector roads roads that typically require traffic to come to a stop (exception: roundabouts).

Local Road. Low-capacity "Neighborhood" road type generally comprised of two-lane or alley roads servicing residential areas. Close/numerous intersections on local roads are generally not dangerous.

Neighborhood. Residential areas. The optimal neighborhood layout may converge a number of local roads into an access road leading to a collector road.

Street Hierarchy. Each road type serves a specific purpose and services different types of areas. The size, intersection complexity, and level of access differs depending on the area to be serviced and the amount of traffic. Read here. https://en.wikipedia.org/wiki/Street_hierarchy

Turning Lane. a diverging lane provided at an intersection to allow vehicles to turn without actually entering the intersection and interfering with through traffic, aka slip lane.

Sim Behaviors

Here are some general items for your awareness that are not readily apparent but will greatly help you in you city planning.

- Sims prefer the highest speed roads/transit options to go between destinations.

- Sims don't particularly care how far they have to go to their destinations. This means you can comfortablly place industrial zones as far from your urban areas as you like and they will still develop and work properly.

- Sims prefer public transportation as long as they can reach a destination as fast as, or more quickly than, using the highest proximal high-speed road(s).

- Sims determine what route they will take when they leave for their destination. Sims will not amend their routes based on traffic conditions. This can be a bane for poorly designed road networks, but a boon for carefully designed ones.

- Sims travel to work (industrial, commercial, and office zones) from residential zones. Sims generally travel to commercial zones, landmarks, and parks before and/or after work. Commercial zones are the epicenter of traffic as goods and people both need to flow into these areas.

Sim Transit and Well-Being

It is important to understand the general flow of sims and the effect of pollution. Sims thrive in low-noise, low pollution environments (away from commercial and industrial zones). Sims' health and happiness are negatively impacted by exposuire to these zones, inhibiting development.

Sims travel to work (industrial, commercial, and office zones) from residential zones. Sims generally travel to commercial zones, landmarks, and parks before and/or after work. Commercial zones are the epicenter of traffic as goods and people both need to flow into these areas.

The worst-to-best heirarchy of suitability for proximity to residential zones to other zones is as follows:

• Industrial. High noise and pollution.
  
• Commercial and transit. High noise.
  
• Office/parks. Low noise/happiness buffs.

Given this logic, the best cities (in terms of traffic) will have the following features:

• Commercial and industrial zones are placed on collector roads, the latter prefereably close to arterial roads, enabling easy and high-capacity access.
  
• Neighborhoods are created at a distance from commercial and industrial zones, the space between being occupied by office zones or open spaces (parks) .

Road Hierarchy.

Road hierarchy is not precisely a mechanic but not observing good practices here can be disastrous. Sim behavior is closely linked to road heirarchies in that have a good understanding of it and planning accordingly enables maximum traffic control. In order of connectivity and quantity, roads are constructed as follows:

Arterial Roads (freeways) < Collector Roads (main roads/highways) < Local Roads (neighborhoods)

If you do not maintain this heirarchy in your city layout, you will nearly always end up with traffic problems in your city. I often see this when folks do not make proper use of collector roads--that is, people do not specifically design roads as collectors. You are going to have a hard time if you only use a freeway < neighborhood road hierarchy. Here is such an example showing how this approach can totally fall apart:



In this example of what appears to be a city center, road heirarchy is not observed. There is no proper interchange for getting on and off the freeway near the developed area. Assuming the roads that stem from the ramps are collectors, they are as numerous as local roads and have many close intersections (~10 u apart) .

Collector roads need to remain mostly free-flowing with few intersections to work properly. Collector roads should be lengthy and provide connection to large areas of the cities, not choppy with many interesections or terminating into local roads after a short distance!

Collector Road Configurations and Industrial Traffic

It is important to provide sufficient collector road access to your work zones. If you are finding all your traffic is funneling into a single road to reach its destination, reconsider the above rules. More collector roads/directions of access automatically reduces traffic congestion.

The number of collector roads required to service an urban area increases massively as the distance from an arterial road increases. Don't expect one collector road to adequately service an area 100u from your arterial road connection.

The take home here is that providing more directions that a commercial zone can receive goods significantly improves throughput. If you have a single road clogged with donut trucks, consider if you can relocate some of your industry to another location that can service the commercial area from another direction/collector road.

Zoning

Implementing good zoning practices and street hierarchy will promote good function of city services and prevent traffic problems. Zoning high-density residential and commercial areas clustered in the center of your town will promote walkability, reducing sim reliance on cars to get around. Having good dedicated collector roads with city buildings clustered near the center will allow services including mass transit and safety/health care to get to their destinations very efficiently.

The following examples illustrate two very different city design styles, the impact of the build approach on walkability and how this information can be used to maximize your city performance. The examples use some highly simplified, miniaturized city designs for explanatory purposes. For the purpose of the discussion, a 20-unit area will be described as a "block."

In the following example, we have a single, two-direction, very long road collector road leading to the center of a high-density city center (blue arrows). Residential and commercial areas are all zoned along the road. The overall width of the high-density area is eight blocks:


The good point of the design is the general zone order in the center of the town we have commercial surrounded by office areas. Office areas will buffer noise pollution affecting the residential zones created by the commercial zones. High-density residential is closest to the center followed by low-density, decreasing the travel distance to work/shop.

However, this design has some problems. I can tell you from life experience, because this is how my old town was designed (one "main street" maybe 3 miles long), as are many american towns. Here are the issues:

• The single collector road means all the traffic will need to funnel into the one, 2 direction road to get to work/shopping destinations. This can lead to heavy traffic.
  
• The area is not very walkable. Suppose a sim lives at the edge of town and works in the most distant office zone. The distance is pretty far to walk--five blocks (120 units). Remember, sims will choose to drive their cars to traverse long distances.
  
• The build is pretty boring. It doesnt look good and and doesn't provide much in the way of ideas for spicing things up.

To solve these problems, you will need to think of your town in multiple dimensions. If the first example shows planning in the X dimension, the following example adds a Y dimension, resulting in a much more efficient, and I would argue the absolute most optimal and realistic, configuration. In this case the total zoned area is nearly identical to the first, but configured in a very different way:


The advantages of this design are as follows:

• The city center has 4 collector roads leading to work/shopping destinations. Assuming all sims take their cars, traffic efficiency has been increased by 100% over the first example!
  
• The area is highly walkable. Assuming the same sim that lives on the edge of town wants to work in the most distant office zone, he only needs to travel less than three blocks (50 units) to get there (half as far as in the first example!) and will likely walk.
  
• The build is interesting. It has opened up the possibility to build a nice green area or square in the center of the town that not only can be nicely decorated, but further promotes walkability, providing a pedestrian shortcut with paths crossing in the middle instead of roads for sims to get around.

Industrial zoning, not shown in these examples, is dirty and should typically be zoned away from your city center. Disperse industry zones at the other ends of your collector roads, giving a buffer from your sims and providing multiple avenues for goods to get to their stores.

Now don't get me wrong here. I am not suggesting you should go build your city in a big grid--these examples are purely for hypothetical purposes and learning. Just keep this scenario in mind to help you conceptualize the configuration of your city to maximize walkability and prevent traffic issues. Now go build something actually interesting!

Now you may be wondering, why discuss inter-city topics before we have even created our first city? Well, I am sure you can agree trying to add an effective rail network into a fully developed city can be a nighmare. That's why the best way to create good transportation networks for your city is to plan the network very early in your build rather than trying to add it in later. Heck, why not start your build with placing a train station before you build any roads at all?

This brings us to the topic of transit-oriented development (TOD) Here's a couple pictures to give you the idea:


Jokes aside, TOD is about creating an inter-city transit network in which transportation hubs are located where the most people are and want to be. Simply put, your center of transit is surrounded by areas of high-density development. Your high-density residential and work areas are all within a very nice, potentially walkable distance to the transit hub, becoming more dispersed and low-density as you move away from that center. This means having your transit hub in the middle of town is a great idea. Going back to our previous city center/zoning example, Here is what TOD looks like for us playing cities:


Here our nice central park area turned out to be a great spot to put our train station. Most sims that want to travel to the next city are within just two blocks of the train station! Our bus lines converge in the center via collector roads giving access to the station and work areas for residents in more distant low-density areas.

For particularly large cities, you may want to have your rail diverge into a freight station located near this high-density development area (not shown). This will allow goods to be delivered to your commercial areas bypassing the road system, saving you the traffic headaches caused by incoming industrial traffic mixing with local town traffic.

One thing you may have noticed is that freeways are conspicuously absent. Freeways do not belong in the middle of cities. If you want a modern and efficient inter-city transportation network, the cornerstone should be mass transit rather than freeways.

For TOD to work the best, you should continue your crusade against personal vehicles by making it inconvenient for sims to use them, and making it super convenient for sims to walk and use mass transit. Here is TOD in full action. The hastily shaded areas show zones of high (red) to low (green) zoning density:


Here are the reasons why this layout works and why you want to pursue TOD in your city:

• The cities are connected by fast freeways, but travel is discouraged because of the indirectness to get between them via this route. The cities are also connected more directly by collector roads, but these only offer slow speed (small/moderate size) and sims like to go fast. This means travel will be mainly limited to low-residential transit and industrial transit and not preferred.
  
• High-density city areas are directly connected by fast rail. Sims will prefer this mode of transportation because it is the fastest option.
  
• The layout is cheap and efficient. Cheap bus lines service the low-density areas. More expensive rails service the high-density areas. The mixing of inter-city traffic is minimized because of the good transit options.

Conceptualizing Map Development

Choose a map you like, then consider your fundamental city plans/objectives before you even begin laying roads. Highly recommend mining the workshop and googling around to find some nice user-created maps that generally offer much more intricately detailed map options to start with than the vanilla options. Starting with a good map automatically puts you ahead of the game when building a beautiful new city.

Assuming you picked up 81 Tiles, you have a lot of latitude in where and how to start your city. Is this a short or long-term build? Do you want it to be European, international, or maybe a blend? Do you want to have a nice relaxing game building a few small, low-density towns? Do you want to build a small-to-moderately sized city with nearby towns? Do you want to make the whole place one high-density dystopian megacity (Shoutout to Killian Experience)?? There are lots of ways to develop a map so try out different things to keep it interesting!!

I recommend to develop satellite towns/districts towards the extremes of the map that ultimately converge in the center via several arterial and collector roads. This provides good access of goods and sims to the city center from multiple directions. Moreover, building each town is like its own minigame and connecting them together later is a lot of fun and looks very realistic. Here is an example we credit to youtuber Silvarret demonstrating how this can work:



Consider interesting locations where you may want to develop. Its generally a good idea to plan your highest-density area near the center of the map. Nice valleys, rivers, peninsulas, and shorelines are much more interesting areas to develop than bland, flat plains. If you have unlocked buildings you will also be able to view the location of natural resources which can help you choose areas to develop industry.

Terraforming

It is good to begin by levelling your city terrain. Using the "level terrain" tool to survey your map is also a good way to begin to help you identify the relatively level areas. Valleys are usually a good place to start as they usually have a pretty level base. When you have selected your city area, do some terraforming with the tool to ensure that the main area targeted for development is nice and flat to avoid some weird plopping and visual issues.

This is also true if you are building on a waterfront and want a nice clean edge for your city perimeter or harbor (e.g. quays or harbor ploppables). You want to:

1. level the entire surrounding area to the desired height, usually just barely above the waterline.
2. create a perimeter using roads.
3. add in harbor ploppables or quays along the road.
4. re-level the terrain to match the seabed level.

here is an example of how to begin:



Below is a potential result of this development method. The area was designated an industrial zone and I used harbor edge ploppables:

Connect a City Center to Arteries Via Collector Roads.

Having a good, dedicated collector road network is a fundamental development step in avoiding traffic jams later on by ensuring that traffic entering cities from arteries can keep flowing nicely.

Collector roads/highways will be the go-between for your freeways and neighborhoods. Most of your traffic will be funnelling through these. Collectors are typically best comprised of 4-6 lanes which gives sims some options for queuing at intersections, improving the flow of traffic. With that said, you don't need to go crazy with collector roads and shouldn't, though they will be more numerous than your arterials giving access to key work areas.

Determine where your city center will be located--that is, the spot that should be the main hub for trasportation, commercial zones as depicted in the previous section. Ideally the city center needs to be acessible by multiple collector roads/transit infrastructure. Next, start by laying out a some basic collector road infrastructure (between 1 and 3 roads is good depending on how far away and how high density the city center will be) using free-form roads converging towards the city center so it looks neat.

Below is an example (arterial in red, collector in blue). The city center will be low and high density, built near the 4-way intersection point between two main collectors.This city center provides two points of access to the arterial road allowing potential industrial service from the east and west along the artery:


Determination of Collector Road Requirements.

For high-density areas in particular, regardless of the quality of the arterial--collector interchange, the number of collector roads required to service an urban area increases massively as the distance from an arterial road increases. Don't expect one collector road to adequately service an area 100u from your arterial road connection.

Consider a scenario in which a single collector road is available to service a commercial zone. Imagine that the collector road is 12 units long zoned with commercial areas and stretches directly from an artery, servicing 6 commercial buildings. Lets assume that one truck coming from an arterial road is required to serve each building. Under this configuration, 6 trucks are travelling along the collector road via one route. Lets assume this means 20% capacity of the interchange is utilized.

Now increase that commercially zoned collector road to 120 units long. Since we still need one truck per each building, now 60 trucks need to travel through the same interchange along the one route to make their destination. Now the traffic load on the route has increased to 200%. Your traffic has come to a complete stop! If you equally increase the available collector road access to the zones by x2, you will may be able to minimally meet the demands of the zoned road (100% each).

Now consider the following scenario. your commercial area is still 120 u long, however you have Collector road access from industrial sectors in three cardinal directions. incoming traffic has three points of entry--from the east, west, and south. This reduces your load on the artery in question to ~70%.

The take home here is that providing more directions that a commercial zone can receive goods significantly improves throughput. If you have a single road clogged with donut trucks, consider if you can relocate some of your industry to another location that can service the commercial area from another direction.

Don't worry too much about interchanges at this point. Interchanges should be designed based on the quantity of expected traffic in the area and will be added in when you have a better idea what needs to go where. Once you get an idea of zoning and the size of the developed area, you can best choose appropriate interchange options.

Next, think about how you will implement zoning around your collector roads, without necessarily zoning it right away. It is a good idea to have an idea of how you want to zone before you move on to the next step as it will inform your choices. Here is an example:


A city center will be constructed at the point where the collector roads converge, not too far from the artery. This will be the main way for sims to get in and out of the city and will be the point where they congregate. Commercial zones will be concentrated along the collector roads in this area, surrounded by offices to buffer against noise pollition.

Industry will be zoned proximal to the artery to the northwest. This will grant direct access to the commercial zones via the artery and then the collector roads, allowing the traffic to largely bypass residential areas. Later another industrial area may be created in the east, allowing goods to be delivered from multiple directions and reducing congestion.

The spaces between the collector roads closest to the commercial areas will be used to zone Residential areas. The advantage is that Sims delivering products from the industrial zone are generally using different roads and coming from a different direction than those just travelling into the city center to work. Also sims can pass through the city center on their way home from work, which is good for business!

Add Arterial-Collector Intersections.

Next, adjust road elevations, creating grade separation between arteries and collector roads to prepare for construction of freeway interchanges. Grade separation is key to building interesting, realistic and effective interchanges and will also be needed later when connecting arteries to other arteries (see section in Inter-City Transit). This typically means elevating or sinking arteries to allow the passage of collector roads. In the below example the freeway was sunk with Move It! mod:



After, add interchanges to the intersections of arterial and collector roads. Good interchanges are critical to effective traffic control. Interchanges rarely need to be complex; given a well planned city, a well-designed basic interchange is often sufficient for all but the heaviest of traffic. Remember--sims follow the rules of the road which makes things much more manageable than in real life. Ideally you choose an intersection based on a correctly anticipated level of expected traffic. Traffic can be anticipated by considering where you intend to concentrate zoning that constitutes places to work (industry, commercial, office). There are no "perfect" intersections. One interchange type is not necessarily better than another--it simply depends on how much traffic the area will see and is a matter of constructing one that is sufficient.

Below we selected a very basic Diamond interchange with turning lanes, suitable for low-density traffic. The interchange includes two lights at the entrances to the overpass. These are cheap, very simply constructed, versatile interchanges that don't take up much space and accept a moderate amount of traffic:



Note that the access ramps are generous in length (~25u). Do not construct very short on-ramps (<15-20u) as this may obstruct arterial traffic by hampering the amount of vehicles that can queue at the intersection, potentially overflowing into the arterial roadway. Also note that the desired direction of travel at the crucial intersections have been specified using Traffic Manager: President Edition. This ensures that traffic using turning lanes always goes right and doesn't try to make improper U-turns which would disrupt oncoming traffic. Refer to Appendix 2 for more complex ideas on arterial-collector intersections.

Add Collector-Collector Intersections.

Make your connections between these roads. The intersections should be more elaborate than straight connections to promote good traffic flow. You should not have more than a four-way intersection at any given point! More is madness for traffic, the exception being rotaries where you can maybe squeeze in five if your roundabout is particularly large. Three ways are particularly nice. Following the discussion below there are additional examples in Appendix 1.

Turning Lanes.

Add turning lanes to key collector road intersections to make traffic flow as smooth as possible. Adding turning lanes allows an easy interchange at an intersection location without needing to stop. For right-hand traffic, this means adding lanes that diverge from main roads onto other main roads in right-hand directions:



In this simple case, a turning lane has been added to enhance an intersection of two collector roads and curved using the Move It! tool. This allows turning traffic to bypass the stop light junction as it enables travel to the left-right road without interference (the traffic is all headed in the same direction). Besides, it looks pretty cool.

When traffic arrives at the turning lanes, The two lanes diverge into separate lanes: a single straight lane going to the intersection (going to a two-way road), and a single right turning lane. This configuration maximizes the throughput by dividing incoming traffic into that which must pass through the stoplight (for left and straight travel) and allowng the rest to bypass the intersection without stopping (right travel only), reducing the load on the intersection. Traffic Manager may be used to direct right-turn traffic into the closest lane (not yet Traffic Managed in the picture), while remaining trafic utilizes the lanes closest to the median.

Number of Lanes.

Ideally, the number of lanes entering a road/intersection is minimally equivalent to the number of lanes transferring traffic in the new direction. An example is provided below. The location is the convergence point of collector roads intended to be the city center shown in the previous section. Note that two four-lane roads are converging at this intersection with one one-lane turning lane diverging from each direction. In each direction, two lanes of traffic resolve into two lanes:



For arterial and collector roads resolving X number of lanes + n is always acceptable (e.g a highway single lane ramp into two diverging lanes), but risky to resolve X number of lanes into X or X - n (e.g. converging two 3 lane highways [total six lanes] into a single highway) and should always be avoided. It is usually ok, however, to resolve X number of lanes into X for lower traffic collector road intersections (e.g. two converging two lane roads).

Weaving Problems.

Lastly, it is important to prevent situations that will cause vehicles to have to weave to reach their destination. Weaving occurs when intersections are particularly close together and vehicles conflict at a point because there is no room to operate:


Alright, maybe this below stolen artist's rendition (thanks source) is more clear in demonstrating the issue...


This can be solved by 1. ensuring that access roads leaving the highway are placed before access roads exiting (above right) 2. adding frontage roads like so:


If initial intersections prove inadequate, you can easily upgrade an intersection by simply adding a section with additional lanes/turning lanes without needing to redesign the whole shebang (examples given below)--you may find that simple, incremental improvements will support loads more traffic!

Dont be afraid to make some free-form interchanges following these principles! These can look cool and add a lot of character to your city and are all but necessary for connecting freeways at odd angles.

Every city should have an interesting and unique city center. The city center typically has some open areas and is a hub for commerce and transportation in the city. Once you have layed your basic road infrastructure and have an idea of how you will later develop the city, it's a good time to start laying out your city center. Below is an example of how you might create yours:



Let's talk about some of the key features of this city center:

Location and Access. The center is located near several main roads for good access. Entrance to the highway is a short distance away on the right while not being smack-dab on top of it. There is a collector road running from the highway to the city center giving access in the east-west direction. Note there is a second main road to the left, providing access from north-south. This means traffic can freely get in and out of the area from many directions which is always a good thing!

Open Space. Now I know for you Americans out there this may seem like a foreign concept but the city center doesn't necessarily mean densely clogged with buildings! There is a large park in the middle at the intersection of the collector roads with a network of paths that will give pedestrians more direct options for getting around the area. Consider use of patios, plazas, gardens, etc. in designing these open spaces. This key feature gives the area some character while also providing a nice place for sims to hang out. I mean, I would want to go there! In addition, it thins out the zoning around which will help reduce traffic congestion. If you prefer a cobblestone/brick look, a neat trick is that you can place pedestrian paths to give access and later cover the area with the desired decals which can completely conceal the asphalt if desired.

Zoning Design. The areas around here are going to be commercial and office zones to give your sims something to do and buy while they're around. You can use Move It!, Plop the Growables and Ploppable RICO mods to get them arranged the way you want, because vanilla game will do some weird things when it comes to curvy roads. You will need Surface Painter to paint asphalt and clean up all the weird edges. There are some open spaces around here too, which can be filled with nice props, parking, decorations, etc. using Prop and Tree Anarchy. You will need to mine the workshop for these.

Transportation. It's a good idea for some transportation services to converge in this location. In this case we have selected buses and utilized a part of the open area as a parking and drop-off location:


This has a number of great benefits. Note there are no stops on the actual roads nearby which can get in the way of regular traffic--the buses have some room to operate in their own dedicated area. Even the access road to the stop is stationed off the main roads! The routes are running off in every direction along the collector and arterial roads which funnel sims in the right direction. The buses are dropping off sims right in the heart of your city where they will work and shop, encouraging them to use public transportation options. In bigger cities, add metro, tram, and train station access near this area to really get those sims moving around!

As always, use your imagination. Google is your friend for generating ideas for a city center. Have fun with it!

This part is pretty simple. Place services in a central location along your collector roads. Your newly created city center is a convenient spot. This allows the service vehicles easy access to many important roads, maximizing their coverage area. Choose the size of services according to the size of the area that needs to be serviced. As for plumbing, it's usually good to place your main lines along your collector roads and later add diverging lines to cover neighborhoods, minimizing the overlap and saving you money.

Local Roads

Finish your road layout by adding in your local roads where you will develop neighborhoods. Neighborhoods do not typically connect to arterial roads. They have a handful of connections to collector roads or bypass them entirely using over and underpasses. There can be many connections between local roads without much impact as they will mainly be seeing residential traffic. Minimize access points from neighborhoods to collectors (>/= 20 u apart is a good rule of thumb). It is also good to limit intersections to three ways. Example below:



If you want a very high density area, grids are not the enemy. Start with grids along collector roads and then get creative. Neighborhood roads are more grid-like nearest collector roads and become more free-form in the spaces in between.

Zoning

Now you can finally go ahead and zone your city. If you will be using growables its good to start zoning districts and allowing them to develop before moving onto the next to avoid growth problems like gaps in the power grid or worse, the dreaded death wave that comes when a million sims move in and die at once.

Remember that zoning is as important as road layout. Always stick to your guns when it comes to zoning. Remember, if you try to start building commercial zones too far from your city center, you will end up with gridlock. If this happens, look at your zoning selections and see if you need to re-zone. If all else fails, reorganizing your zoning is not fun but can be a big help in solving traffic problems.

Assuming you did not go the TOD route, now that you know where your main roads are going to be and where things willl be zoned, you can effectively select and place additional transit services. While your heirarchial road infratructure, intersections, and zoning choices constitute your blueprint for traffic control, mass transit options comprise your toolbox. Make sure your sims have lots of ways to get around the city.

Your mass transit network needs to cover your collector and arterial roads and give access from residential areas to work areas to most effectively save car trips. Sims don't mind travelling a few blocks on foot or a few more by bicycle, but beyond that they are going to take a car or public transportation. Remember sims will prefer the shortest distance and the fastest mode of travel to get around!

Conveniently, much like your road network there is a transport heirarchy. The below transportation options are given in order of number of fastest travel speed, highest quantity of sims that can be serviced, and the least number of services you will likely have per type to the slowest, fewest, and most numerous.

Trains. Use trains to whisk sims between between and across cities. These often run along the same routes as arteries but can also cut through wilderness and sometimes neighborhoods. I would not space out train stops any closer than 300 u apart. Very expensive but necessary to get that cool factor. NOTE: there's a mod that let's you adjust ticket prices so you can actually be rewarded and MAKE money off of good ridership. Forgot the name... go find it!

Metros, and Monorails. Place these along major collector roads to connect districts of large cities. Particularly good for very high-density cities as they have a small footprint and dont contribute to local traffic. Space these >/=150 u apart.

Trams and Buses. These are a slower mode of transportation but serve the purpose of getting sims between blocks and for cheap when it comes to rural or low-medium density areas where it just doesnt make financial sense to have an elaborate rail network. Run these along your collectors as well including less important ones where you're not going to build subs. Particularly with buses, these can cut into large residential areas to make pickups if needed. Usually a stop every three blocks or so works well (50-60 units apart).

The issues with buses and trams is although they are more cost-effective than rail, they will still contribute to traffic. Make sure that the bus depot is placed near arterial roads and and large bus stations near the center of town ideally with dedicated access as described in the City Center section to prevent congestion.

Ferries and Blimps. For those efficiency buffs among you I bet you are wondering what the heck to do with these. While slow, Sims will use these when they provide a really direct route between areas that have natural boundaries otherwise only connected by lengthly roads or railways. Need to cross wide rivers, lakes, or large bays? Use a ferry. Is there a big old mountain range between your cities? Use a blimp. Sims would rather take this snail transportation than have to take winding roads around to get there. Plus, cool.

Aterial Connections

Later if you want to build multiple interconnected towns and cities on the map, You will need additional arteries and some more complex interchanges to ensure your highways remain free-flowing. This means large interchanges with long access ramps and free of areas that contribute to congestion. Larger, more generously sized interchanges will always work better than small ones with short ramps to a "receiving" highway which can allow cars to pile up and obstruct traffic along the "sending" highway. Also, tie your cities together with your web of collector roads to give even more directions of access.

Weaving conerns apply in building these roads and at high speeds are as important as ever. Prevent situations that will cause vehicles to have to weave to reach their destination. Additionally, be aware that harsher curves result in a reduction in traffic speed. Both of these factors will reduce the throughput of your interchange. These issues are minimized in interchanges like a turbine or stack and are why they are so much more effective than a standard cloverleaf for example, which has close on-and-off ramps and very tight loops.

Refer to Appendix 3 for more examples of arterial interchanges. Dont be afraid to make some free-form interchanges following these principles! These can look cool and add a lot of character to your city and are all but necessary for connecting freeways at odd angles.

Inner City Arterial Connections

Ok, be warned, this section is going to get a bit hairy. It is likely your main city center is going to end up near a major arterial intercehange and you will need collector roads access not miles away. With that said it is very important you put together good collector intersections very close to this interchange in order to succeed. To build good collector intersections in such a location you are going to need to apply everything in this guide to do a good job. Use the below methods to make this happen.

Think out of the box here. Just because we have arterial interchanges does not mean we cannot have good (albeit complicated) collector road interchanges nearby. We just need to be smart about the configuration.

Here is an example of a situation where we need to build collector roads near such an intersection. the situation is a couple arteries connecting at a very harsh angle (< 45 degrees).



The idea is to leverage arterial access roads as frontage roads to access collector roads. The benefit is that the arterial intersection goes unhindered in terms of flow while the ramps branch off in diverging directions to connect to collectors:



Here we have two collector roads passing near the aterial intersection. Below we show the connections in terms of the arteries (red), collector access roads (green), and collector roads (blue) while arterial interchange ramps are not highlighted:



Standard diamond intersections are used in each case but could be improved as shown in Appendix 2. You will notice that frontage roads/local expressways are key to a good design in that the through traffic on the arteries is fully separated from that which is entering the collectors. These are the mode for accomplishing this as we have diverging traffic off the ramps (remember traffic diverging is always better than converging) and not adding additional connections the artery. The arterial ramps are leveraged 100% to give access to the collector roads, which in most cases means that arterial traffic is split up rather than converging in the intersecting locations.

All the collector roads have turning lanes so trafific can smoothly enter or exit the artery where right turns are permitted. However, be judicious about your connections. Because the collector roads are close and there is not much room to work with; in the case of the northwest collector connection we do not have a full diamond interchange which would complicate the traffic changing arteries in the low-right center. Everywhere else that is is possible, we have diamond collections to the artery via access ramps.

Having good traffic flow is important to the growth and well being of your city. Poor traffic flow results in slow or negative growth, poor service performance, and just plain makes you sad to look at it. Unfortunately traffic problems are one of the toughest things in the game to tackle for a learning player. In this Appendix I will walk you through the process of analyzing your potential traffic problems using the "Fix the Traffic" scenario as an example, depicted below. Traffic flow is a pitiful 57%! First let's take a holistic look at the city to break down the main problems:


1. There is heavy congestion where the freeways connect in the center of the map, due to this being the only route for traffic to get between the east and west, and poor interchange design.
2. There are too many interchanges next to each other, leading to congestion, as a result of traffic trying to get on and off everywhere.
3. Arterial/collector interchange design choices are poor at key locations.
4. The districts are suffering from island syndrome. Generally all the traffic from a given district is funnelling into one or two roads connected to the freeway to get around. Areas of high density and industry either do not have ample access routes to the freeway or are not interconnected by collector roads.

Now lets disect the biggest problem areas in greater detail and examine the selected solutions.


1. Three freeways were connecting too closely to each other. The interchange design was poor. The interchanges were replaced, reducing the number of freeways from 3 to 2. A parclo interchange was selected as it was a good fit for the odd angle of crossing.
2. The cloverleaf was too large, not giving room for traffic exiting to queue after leaving the freeway, leading to backups. The clover interchange was also too close to the artery interchange, giving weaving problems. Changed to a dumbell interchange, giving room for traffic to queue and for adding local expressways (frontage roads) which separated exiting from through traffic.
3. The industrial district had only one connection to the artery. Added additional connections to the artery and other districts to spread out the traffic.


1. Too many interchanges and too close together, resulting in poor efficiency of traffic trying to get on and off. Changed most of the interchanges to overpasses as they were not needed.
2. One interchange giving access to the commercial area was redesigned. The diamond interchange gave no room for traffic to queue exiting the freeway. Replaced with an elongated roundabout, selected mainly because it fit in the tiny space.


1. The major commercial area had only one route of access, from the north. Added a small highway that connected to the southern leg of the freeway to spread out traffic and allow additional ways for traffic to access the area.
2. The major district to the east had no collector road connection to the major district to the west. The lack of connection to the freeway was also a missed opportunity to spread out traffic. Connected the districts via the new highway using a diverging diamond interchange (I swear!), selected because of limited space to build in the area.
3. Added another way for the industrial sector traffic to get to the eastern destination, spreading out traffic.
4. No connection for this high-density area to the freeway. Added one in.


1. The interchange design at the freeway endpoint was too small and a weird shape, resulting in too many stops getting off and poor distribution of traffic. Replaced with a large dogbone, selected because of the number of connections that could be safely made to it.
2. Only one connection to the large district to the south; replaced with two connections to disperse traffic.
3. Only one connection to the industrial district to the north; replaced with several connections including a dedicated access road from the freeway. Only traffic needing to go west or south would therefore enter the dogbone.

Phew, these improvements really helped out. Here is how things are looking now overall. Things are running smoothly and our traffic flow rate is up 25%!!!


One of the main overall points I want to draw your attention to is the addition of collector road infrastructure, highlighted in blue. The city originally had very few collectors, leading to poor interconnectivity of districts. You will recall that collector roads are lengthy main roads with limited intersections, giving access to the high density and industrial areas as well as other ways for sims to get around other than the freeway. They are also critical to building a functioning mass transit system. The new connections that were made to create them were chosen carefully to accomplish this, putting an end to the dead end disorder plaguing this city. As a result the burden on the freeway went way down and congestion in individual districts was improved.

Below are some examples of higher-capacity intersection configurations suitable for collector-collector changes in order of cheapest/easiest to construct/least throughput to most.


Upgraded intersection. Super basic, but demonstrates how throughput can be very easily improved by adding a section with addtional lanes that allow vehicles to queue and turn more efficiently at the point of intersection.


Intersection with turning lanes for even more throughput.


Basic rotary. Good throughput with no stopping. Note that additional nodes (the gray circles) will need to be created to allow traffic to change lanes. Here it can easily be accomplished by building an X using roads, then deleting them. Applies here and below to all rotary designs.


Rotary with diverging access roads. Better throughput with no stopping and looks nice.


Rotary with diverging access and slip lanes. Best throughput but expensive and big.


Need a pile of lanes and tons of throughput? Do separate carriageways like so and get real fancy with things like this continuous flow intersection. You can use some really innovative, interesting, attractive and effective intersections when you use two to four-lane one-ways rather than the games' two way offerings. Downside is that this is basically a flat baby stack interchange (huge).

Check here for more information on intersections but be warned this one is not as good as the article on interchanges. Click the examples within the body to see some different ones:

https://en.wikipedia.org/wiki/Intersection_(road)

Below are some examples of modern, higher-capacity interchanges for arterial-collector roads from lowest throughput/easiest to construct to highest. Use these to get your sims on and off the freeway. Note you can Invert these designs with the highway above and collectors below in case where your highways are overpasses.


Partial Cloverleaf, this one is based on a real life swiss interchange!



Single-Point urban interchange. Has a single stoplight near the inner exit ramps. Very efficient for the small footprint.



Rotary interchange. Can be circular or oblong. Oblong takes up more space but offers better capacity and more distance between access roads. No stopping. An additional benefit is that it permits U-turns.



Dogbone interchange. High capacity and no stopping but takes up quite a lot of space.


Diverging diamond interchange. Has two total stoplights near the exit ramps. Note that the overpass roads are criss-crossing one-ways to permit traffic easy acess from the arterial to the collector without interfering with through traffic. Make all your friends jealous with this super nifty and innovative design!!

Dont just use these. Following best practices, get creative--mix and match and experiment with odd angle intersections to keep it fresh. Here are a few additional examples to check out: https://en.wikipedia.org/wiki/Diamond_interchange

Here are a few examples of effective, modern intersections from easiest to construct, lower capacity to more challenging and highest capacity. Use these to get your sims from one freeway onto another. Move It! is an absolute must to achieve good (and pretty) ramp curvatures:


Trumpet interchange, for when you want to terminate an artery while intersecting another.



Cloverstack interchange. Thanks Agusingnavy!


Stack interchange. Very high capacity throughput but a massive a space-hog. The secret here is the combination of: very generous turning lanes that don't require traffic to slow down due to their very gradual angle of approach (~ 50u to make 90 degrees), separation of dedicated exit lanes that diverge and converge away from the through freeway traffic, and very long distance between the exits and entrances (~120 u).

I also highly recommend reviewing the following to generate ideas when creating interesting/appropriate interchanges:

https://en.wikipedia.org/wiki/Interchange_(road)

To learn more about the game and generate some good creative ideas I recommend watching videos from the likes of:

• HotKettle
  
• Strictoaster
  
• Skibitth
  
• two dollars twenty
  
• Silvarret
  
• Imperatur
  
• Crumbs McGee

If you want to sit around with a constant erection over the high-res eye candy of your new and improved city, especially if you are in a build for the long-haul (100,000+ citizens), this can be pretty demanding on your hardware. You may find that your game can creep to a halt, especially if you have a low-end PC. This is particularly true in the following cases:

- Using the Move It! and Dynamic Resolution mods
- Having a large number of custom assets
- Having vast amounts of props (im looking at you too, trees)

Limiting these, particularly disabling Dynamic Resolution, should help your performance. If you are not on a very tight budget though, I highly recommend 16 GB RAM in order to run this game to get the experience we are going for.

Thanks for reading and I hope you learned a thing or two. It was a lot of fun to make the guide and I appreciate your feedback including recommendations for any additional content. If you have used my step-by-step guide to make your city, I would love for you to share pictures of your creations and talk about your city in the comments below. Please remember to favorite and rate up!