Hello again! This time we will take a peek at how the game systems actually work. Some of the main goals for us at Colossal Order where to create fun systems which interact with each other, and to have simulated individual citizens.

At the heart of Cities: Skylines is how the individual citizens and goods move around the city. Citizens have a name, age, a home and a workplace, unless they are students at the university or too young to work. Citizens travel to work, go shopping and occasionally visit leisure locations like parks. Not all citizens own cars, so some walk and others drive. If public transportation is available, most of the people without cars will use it for longer trips. Even people with cars use public transportation if they notice driving with their own car might be slower because of the traffic.

Because simulating individual citizens takes some processing power, we opted to cut down the number of citizens. Some residential buildings have a quite low amount of people living in them compared to the size of the building. We felt choosing individual citizens over realistic numbers brought more to the game. So while your high-rise might have only 12 households, everyone has a name and a logical pattern of moving around the city.

Goods are produced in industrial areas and transported to commercial areas to be sold to citizens and tourists. This means that wherever there’s a commercial area, there will be trucks driving to and from it. To produce goods, industrial areas use raw materials. If the city produces raw materials by specialized industry, the industry will automatically get them shipped from the specialized production facilities. Industry prefers materials from inside the city, but if none are available, they will order raw materials from outside locations. Materials arriving from outside locations come by truck if no train or cargo ship connections are available, which will put a stress on the road system.

To avoid traffic jams, vehicles choose their route so that they try to avoid busiest spots in the city. They also like to choose lanes early to avoid switching lanes and blocking off two lanes in the process if they are trying to push their way into a line of cars and have to wait. If the traffic does not flow well, there’s a traffic info view to show the spots where problems lie. Using roundabouts, elevated roads and building roads to get the vehicles straight to where they are going is are a big part of the game.

Everything is connected. If you build a Fire Station that sends out fire engines to put out fires, the service vehicles can only get to the fires if the roads are not crowded with other vehicles. But just having a Fire Station near by raises the happiness of residential houses. A raise in happiness means the residents are less likely to turn to crime, even if they are unemployed for some time.

Karoliina Korppoo, Colossal Order, lead designer on Cities: Skylines

 

[Miwi]

First of all: It's not a tragedy the number of simulated citizens was cut down. Anyway I didn't believe the earlier numbers of 1.000.000 simulated citizens. The only thing I would try to hide is the real number of e.g. 12 households, the 12 could be extrapolated to a realistic number of households respectively citizens, I don't care how many citizens of my e.g. 3 millions of habitants are really simulated, it is ok for me to simulate only a certain percentage. Most important is to see realistic numbers of citizens and reasonable movements and traffic streams in my city. So multiplicate the simulated 12 households with 10 or 15 (not fixed numbers, only an example) and only show the extrapolated numbers and I am fine with it.

However, for the simulation part of the game what practically is the core part, I would have liked to see some more information, but ok the most important things how the simulation behaves were described even though with sometimes only a few words.

 

[Eurofighter1200]

Nice but i was wondering Dev Diary 6 startet on 7.01.15 wtf ? that was the mapgenerator but than it was a new one

So in Cities Skylines we can't have these fails like in the sc 2013 where 100 cars take the same route to the one big skycraper and kills the traffic there i always wonder how can 100 peopel living in so littel towers dont need millions of peopel and 50% of them ae not exists so its good was co is doing.

 

[Co_Karoliina]

The numbering was my bad, sorry! It is Dev Diary number seven and the title is now correct. About the amount of inhabitants in a city, we are aiming for a million at maximum. Even if there's only twelve families in a tower, a family can have more than two children, so counting a family unit as four people is not correct. A family unit can be just one young adult, but usually they have children. With the large map size there can be quite a many houses and still leveling the buildings up and zoning high density residential does affect the number of citizens.

Knowing who the citizens are and where they work also really helps with traffic, because you can just click on a few cars in a traffic jam to see where they are headed and make an alternative route to help out.

 

[Inge Jones]

Now that we're onto the topic of simulation and scalar representation I guess this is an appropriate time to once again ask about how a diurnal cycle will be simulated. Especially since there will be identifiable citizens making purposeful journeys. I want to know, will there be such concepts as "office hours" when office workers will be coming to and from work? Will there be school hours? Will there be rush hours and quiet hours on the roads that the player can notice? If so, can we be able to slow down this day so that it won't just flash past, and so that we can actually see one of these citizens making their journey?

 

[Alexo1]

About the amount of inhabitants in a city, we are aiming for a million at maximum.

Well, I think the idea that you guys have created in the minds of the players was different than that. Cities in your game are going to be huge, right? Than this has to have a realistic representation of the number of inhabitants. The right solution would be to count 2 numbers, one with the actual number of agents, and a more realistic one. You say that a family is not always 4 people, and that's true, but it's very possible to calculate an average of people in one building, that take into count families with 0-3 children, and even having a few representation options in this matter. In any way, it is possible to be done because it doesn't require drastic changes, and would offer the best solution for this problem. I hope very much that you won't discard this topic. We just want to be able to see a big number, and not just the actual one. This is also part of gameplay experience...

 

[Allirion]

Sounds great, that's exactly how I imagined it. Minus the downscaling, but well, my PC would probably burst in flames with a city of a million separately computed citizens.

Happy new year!

 

[Sabarok]

To avoid traffic jams, vehicles choose their route so that they try to avoid busiest spots in the city. They also like to choose lanes early to avoid switching lanes and blocking off two lanes in the process if they are trying to push their way into a line of cars and have to wait.

I wish more real-life drivers would do the same thing. I don't know about anywhere else but, where I live, anytime there's a long line, you can always find someone trying to cut in near the front. Sometimes it's impatience, sometimes it's because they missed the lane change, and sometimes it's because the line extended back before they even entered the highway.

It probably wouldn't be worth it to implement, but it could be interesting if citizens had an experience level with their commute. If they are going somewhere they have never been before, they might be late to switch lanes (causing a choice of either forcing a late merge or passing it to the next intersection, depending on the importance of that turn), or they might miss the turn completely and take a longer route. It adds an element of chaos to the traffic patterns. This could also be paired with economic status. People of middle class or higher might choose to navigate to a new location by GPS, which eliminates those chances, however using GPS could also come with the downside of picking the most direct path without trying to avoid traffic (or maybe upper class will have the more expensive GPS which picks an optimal route factoring in traffic). Maybe for simplicity, this could be driving home & work is always considered an experienced commute since it's something they're going to do on a daily basis, while driving to destinations that are meant to solve their needs might be an inexperienced commute.

This can be extended by tracking a stress level with traffic. The more time a commuter gets stuck in traffic, the more willing they'd be to take public transit, even if they wouldn't be saving time. As an example, if 80% of their commute is traffic, but public transit takes 15% longer, maybe their stress has them 10% willing to choose public transit for their commute instead. As more people switch, traffic eases up, and some will switch back. If there's stress being tracked, it can also be used to increase error rates, such as missing their turn, breaking a traffic law (running a red light or speeding), or even getting into an accident. Perhaps for simplicity, the earlier idea on experience could be tracked through this. When going to a new location, there's added stress, which means the commute begins at a slightly elevated stress level, and this mechanic is what causes the errors of missing a turn or being late to a merge. Each mistake can also come with an elevation to stress. To alleviate it, stress can also go down by driving on course and outside of traffic. You could also have stress influenced by other aspects of life. Being home lowers stress, having a family might cause it to be erratic, and driving with kids in the car might also come with the risk of stress elevations. Work can raise stress, and maybe some industries & jobs cause more stress than others, while providing commercial recreational buildings that lower stress. You've put in a long day at work, it was a bad day, and all you want to do is get home, and this elevated stress leads to impatience, and you run that red light because you just don't want to be sitting and waiting. This gives police something to do by pulling people over, which gives players something interesting to see, as well as playing havoc on traffic.

Perhaps your high-tech executive offices bring in good money, but they also bring in high stress jobs, causing an increase in the demand for local bars & pubs to lower stress.

 

[charlesnew]

I wish more real-life drivers would do the same thing. I don't know about anywhere else but, where I live, anytime there's a long line, you can always find someone trying to cut in near the front. Sometimes it's impatience, sometimes it's because they missed the lane change, and sometimes it's because the line extended back before they even entered the highway.

It probably wouldn't be worth it to implement, but it could be interesting if citizens had an experience level with their commute. If they are going somewhere they have never been before, they might be late to switch lanes (causing a choice of either forcing a late merge or passing it to the next intersection, depending on the importance of that turn), or they might miss the turn completely and take a longer route. It adds an element of chaos to the traffic patterns. This could also be paired with economic status. People of middle class or higher might choose to navigate to a new location by GPS, which eliminates those chances, however using GPS could also come with the downside of picking the most direct path without trying to avoid traffic (or maybe upper class will have the more expensive GPS which picks an optimal route factoring in traffic). Maybe for simplicity, this could be driving home & work is always considered an experienced commute since it's something they're going to do on a daily basis, while driving to destinations that are meant to solve their needs might be an inexperienced commute.

This can be extended by tracking a stress level with traffic. The more time a commuter gets stuck in traffic, the more willing they'd be to take public transit, even if they wouldn't be saving time. As an example, if 80% of their commute is traffic, but public transit takes 15% longer, maybe their stress has them 10% willing to choose public transit for their commute instead. As more people switch, traffic eases up, and some will switch back. If there's stress being tracked, it can also be used to increase error rates, such as missing their turn, breaking a traffic law (running a red light or speeding), or even getting into an accident. Perhaps for simplicity, the earlier idea on experience could be tracked through this. When going to a new location, there's added stress, which means the commute begins at a slightly elevated stress level, and this mechanic is what causes the errors of missing a turn or being late to a merge. Each mistake can also come with an elevation to stress. To alleviate it, stress can also go down by driving on course and outside of traffic. You could also have stress influenced by other aspects of life. Being home lowers stress, having a family might cause it to be erratic, and driving with kids in the car might also come with the risk of stress elevations. Work can raise stress, and maybe some industries & jobs cause more stress than others, while providing commercial recreational buildings that lower stress. You've put in a long day at work, it was a bad day, and all you want to do is get home, and this elevated stress leads to impatience, and you run that red light because you just don't want to be sitting and waiting. This gives police something to do by pulling people over, which gives players something interesting to see, as well as playing havoc on traffic.

Perhaps your high-tech executive offices bring in good money, but they also bring in high stress jobs, causing an increase in the demand for local bars & pubs to lower stress.

That was stressful to read.
No, just kidding, this is genius.

 

[charlesnew]

I wish more real-life drivers would do the same thing. I don't know about anywhere else but, where I live, anytime there's a long line, you can always find someone trying to cut in near the front. Sometimes it's impatience, sometimes it's because they missed the lane change, and sometimes it's because the line extended back before they even entered the highway.

It probably wouldn't be worth it to implement, but it could be interesting if citizens had an experience level with their commute. If they are going somewhere they have never been before, they might be late to switch lanes (causing a choice of either forcing a late merge or passing it to the next intersection, depending on the importance of that turn), or they might miss the turn completely and take a longer route. It adds an element of chaos to the traffic patterns. This could also be paired with economic status. People of middle class or higher might choose to navigate to a new location by GPS, which eliminates those chances, however using GPS could also come with the downside of picking the most direct path without trying to avoid traffic (or maybe upper class will have the more expensive GPS which picks an optimal route factoring in traffic). Maybe for simplicity, this could be driving home & work is always considered an experienced commute since it's something they're going to do on a daily basis, while driving to destinations that are meant to solve their needs might be an inexperienced commute.

This can be extended by tracking a stress level with traffic. The more time a commuter gets stuck in traffic, the more willing they'd be to take public transit, even if they wouldn't be saving time. As an example, if 80% of their commute is traffic, but public transit takes 15% longer, maybe their stress has them 10% willing to choose public transit for their commute instead. As more people switch, traffic eases up, and some will switch back. If there's stress being tracked, it can also be used to increase error rates, such as missing their turn, breaking a traffic law (running a red light or speeding), or even getting into an accident. Perhaps for simplicity, the earlier idea on experience could be tracked through this. When going to a new location, there's added stress, which means the commute begins at a slightly elevated stress level, and this mechanic is what causes the errors of missing a turn or being late to a merge. Each mistake can also come with an elevation to stress. To alleviate it, stress can also go down by driving on course and outside of traffic. You could also have stress influenced by other aspects of life. Being home lowers stress, having a family might cause it to be erratic, and driving with kids in the car might also come with the risk of stress elevations. Work can raise stress, and maybe some industries & jobs cause more stress than others, while providing commercial recreational buildings that lower stress. You've put in a long day at work, it was a bad day, and all you want to do is get home, and this elevated stress leads to impatience, and you run that red light because you just don't want to be sitting and waiting. This gives police something to do by pulling people over, which gives players something interesting to see, as well as playing havoc on traffic.

Perhaps your high-tech executive offices bring in good money, but they also bring in high stress jobs, causing an increase in the demand for local bars & pubs to lower stress.

That was stressful to read.
No, just kidding, this is genius.

 

[Kanimir]

I don't like the idea of cutting down the number of citizens, I'd prefer realistic numbers, even if it means cheating a little bit. I understand that the game wouldn't be able to handle that much simulation, but how about 1 person counting as 3 for example? So we see 1 person going to work, but the game see it as 3. The building has 30 instead of 10 people inside, and the city has 300 000 instead of 100 000 population? It's not like someone is going to count every single person in the game to see if it matches the population. We would have more realistic number of citizens compared to the size of the city/building and the game would run just as fine and it wouldn't affect the simulation.

 

[Inge Jones]

You could just mentally multiply every number by 3 as you're reading it? Or maybe it could be a user configuration option, you enter a figure, and the UI automatically multiplies everything by that number in order to look convincing according to individual convinceability?

 

[Greygor69]

Here's a thought.

Vanilla Cities:Skylines would have 36 km2 available to build upon, IIRC.

With a Million people this would give you a population density of around 28,000 people per square kilometre. That puts you in the top 10 in the world.

You're outstripping Mumbai, Delhi, Seoul etc. for packing people in as tightly as possible.

As far as the US is concerned you're in the top 10 cities with the most population knocking San Jose back to number 11 and it's area is about 800 km2.


I'm not sure the vanilla limit is that big a deal except that people want to see big numbers. It's arguable more realistic considering the area we're dealing with.

 

[Jokurr]

Please allow us to mod the number of citizens in each building, preferrably with even more freedom than in CiM2. There we had a simple scale increasing the amount of residents in ALL buildings. It would be nice if we could mod to keep the number of residents in detached homes the same, but increase those in high rises.

What I'm reading about the simulation sounds good, nice to hear that traffic takes into account how long their planned route might take. I would love to see a livestream focusing on that!

 

[Kanimir]

Here's a thought.

Vanilla Cities:Skylines would have 36 km2 available to build upon, IIRC.

With a Million people this would give you a population density of around 28,000 people per square kilometre. That puts you in the top 10 in the world.

You're outstripping Mumbai, Delhi, Seoul etc. for packing people in as tightly as possible.

As far as the US is concerned you're in the top 10 cities with the most population knocking San Jose back to number 11 and it's area is about 800 km2.


I'm not sure the vanilla limit is that big a deal except that people want to see big numbers. It's arguable more realistic considering the area we're dealing with.

Only if you actually reach 1mln population in your city, but if you'll have less than that, lets say 300 000, it won't be realistic, the city will take more space and look bigger than it actually is. I also don't see how being in top 10 most densely populated cities makes it unrealistic? Is Seoul less realistic than Berlin because it's denser?

Or maybe it could be a user configuration option

That would be awesome.

 

[makinistfanlari]

I hope its "low" graphic mode. If its high, we need modders.

Players:"HEY MODDERS,COME HERE,THERES A GAME SHOULD BE MODDED!"
Modders:"Guys pick up wrenches we have a little work."

 

[uebs]

Now that we're onto the topic of simulation and scalar representation I guess this is an appropriate time to once again ask about how a diurnal cycle will be simulated. Especially since there will be identifiable citizens making purposeful journeys. I want to know, will there be such concepts as "office hours" when office workers will be coming to and from work? Will there be school hours? Will there be rush hours and quiet hours on the roads that the player can notice? If so, can we be able to slow down this day so that it won't just flash past, and so that we can actually see one of these citizens making their journey?

Great question...i think without tracking time this is the biggest flaw in the game.

Its nice people have jobs and homes they go to every day(the same jobs and homes unlike sc2013)...but how do they know when to go to work and when to go home? When to go to school, when does the garbage get picked up.

Maybe it was a solution for traffic...with no time they can have people go to work whenever and go home whenever therefor reducing traffic congestion.

I think time simulation in a city builder is a important aspect, more important than the water simulation.

 

[BrunoDerKaiser]

I love seeing all the desesperated SC4 rats whining about every single detail and subject. Get down to Earth together with your unrealistic expectations. Mods are very important, but they're not magic.

Great dev diary by the way. I look forward to seeing the flow of traffic out of the suburbs into downtown.

 

[Miwi]

I won't purchase the game if I can't simulate the color of underwear of my citizens

 

[Eurofighter1200]

Maybe it was a solution for traffic...with no time they can have people go to work whenever and go home whenever therefor reducing traffic congestion.

I think time simulation in a city builder is a important aspect, more important than the water simulation.

We have time look at the videos there is only no night visually but time is there.

 

[4k547]

I like the little amount of people in the game, kind of like POPs in Victoria 2 but how are you going to stimulate the traffic with such a low number of citizens? In simcity 4 there were many citizens so it made sense there is going to be a traffic. But when you can have lets say 14 road squares per 12 families if you place road like a complete dummy I don't see traffic happening.