City Based Demand systems
This is the first official preview of the new City Based Demand system that is planned to power the new cargo feature, and later also the passenger traffic figures.
Please bear with me as this is mainly a text-only preview since the interface won't have much new to show.What is City Based Demand?
The current method of modelling passenger traffic figures between airports is based on real-life data and statistics of airports, which are then used to calculate the assumed passenger numbers between two airports. These numbers are factored with other values to get suitable results for each game world and each era. This can be called Airport Based Demand
system and it is static and non-responsive to player's actions.
The new demand system, City Based Demand
, aims to free players from the shackles of traditional large real-world HUB airports making the passenger demand figures independent from the airports.
The benefits of the new system are that it makes the game worlds more dynamic, it allows players to develop airport traffic based on his actions and it enables us to create a more detailed economic environment with regional changes in the economy (vs. global at current model). This new model was first suggested already a long time ago, and the (huge) data collection efforts have taken its time. And as with all major features, the development happens parallel to other smaller updates, so progress isn't always lightning fast.
The key to understanding the new demand model is that passenger demand is no longer airport-to-airport, but region-to-region and airports only serve as the gateways between these two points. So the specifications of an airport have nothing
to do with the potential
demand it has anymore (i.e. even the small city airport will have the potential long-haul demand - but in practice in the games the demand will shift to other airports with actual longhaul service).Technical background
To calculate the passenger and cargo travel desire between two points, we've split the world into predefined areas. Each of these areas has certain values and specifications - some of these are collected by our users (thank you!!) and others are loaded from various statistical sources. This way we know for example which area of each country is a holiday resort or an important industrial center.
This background data is dynamic and based on real history - for example the economy trend values are based on actual historical stats, and this allows us to model situations like recessions in some country (see image #1
, this depicts the economy development of a country - there are several points where the economy shrinks or grows rapidly). Using all this data the system will figure out the total potential demand departing from this predefined area (this is not visible to players, just a step in the process).
This demand can then be assigned to any nearby airport. The airport must usually be within the same country, but if the political situation allows border crossings all or some of the demand may also end up in nearby airports in the neighbouring countries.
Each airport has a designated catchment area
which determines the range and amount of demand they can catch from these nearby areas. This catchment area changes over time based on the size of the airport and can be between 50 to 200 kilometers depending on the size classification of the airport. (see image #2
, an example from the admin interface that shows the catchment area of a regional airport)
Finally this demand caught by the airport is calculated together and will be presented to player in the familiar "airport to airport demand" chart. So the interface of the game will not change that much - the players will still research demand between airport pairs like already now. But the big difference is that airports are now only facilitators of the demands generated by cities and other areas, like in real life.Demand can be caught by many airports
When a game world starts, a demand from an area is very often caught by many airports with overlapping catchment areas. Think for example Tokyo with two major airports, Haneda and Narita (see image #3
, the catchment areas of the airports are overlapping and the airports "fight" over the same demand). Both of these airports catch the area of greater-Tokyo.
This means that the local area demand from Tokyo area is directed to both of these airports based on the distance to the airport and the size classification of the airport. The closer the airport is and the bigger it is, the more demand it will receive from this area. This means that basically the demand for Tokyo area is shared by these two airports (other airports may catch parts of the demand too if they are nearby, but it will only be fractions of the total since they are not so close to the city).However
, and here's the beef, if the other airport (let's say Haneda in this case) is not being served, the demand will gradually move over to the other airport. So after a while the Narita airport would then catch all of Tokyo's demand and would be a very big traffic center. This will then work the other way round too - if later on someone decides to start the routes from Haneda, the demand will then gradually move back towards it (note that due to the technical structure and large scale of the system all of these demand shifts are gradual and take a fair amount of time). This dynamic demand will be previewed in action later when it's finished.
There are many other cities and areas that are served by several airports. Like London, New York and Paris. Effectively this means that the big cities will have now much more competition as the many airports sharing the city will fight over the same demand and the demand is not fixed to the airports anymore. So you won't just compete with the other airlines at your base airport, but with other airlines at other airports nearby - just like in real life. This also means that the old money maker airports like LHR might not be as lucrative as they used to be since the demand from London can be served by for example Gatwick instead of Heathrow (depending on the player's actions).
Once again, the airport only serves the demand and the specifications of the airport have nothing
to do with it. So for example initially
the small London City airport will have very much long-haul demand to for example North America since it serves the big city of London, but if (and when) nobody will serve this demand it will move to other airports in the area (but the potential for it remains if someone were to start such service later). The runway and slot restrictions at airports make this interesting too - would you start at a small city-center airport with more demand potential than the suburban big airport but risk being limited by the infrastructure (and wait many years for the small city airport to expand, if ever..)?Traditional big HUB airports won't be big anymore, necessarily
Since the whole demand system will be based on city areas instead of airports the real-life big HUB airports that are big just because there is a big airline present but little local demand (like Atlanta) will lose their meaning. Atlanta area airports will have only the demand from the Atlanta city area (and surroundings) - so for example airports in cities like New York and Los Angeles will have a great deal higher demand numbers since they serve big cities.Can I build by own big HUB?
Players can indeed make the airports grow and create traffic to airports that would be otherwise quiet. For example you could find a small city airport that will catch the demand of a big city (like Stockholm and the Bromma airport) and start flying from there. Initially your problem can be that the airport might be capacity limited but future versions of this system will allow airports to expand with new runways (more slots) and so forth.
The model of actual flight connections (= fly between points 1 and 2 with transfer to other flight at airports 3) won't be modelled yet at the first release. There are initial plans for it but the development of this whole new demand concept will be made in smaller steps in order to be able to integrate the systems to currently running game worlds.Only for cargo?
Yes, the new demand systems will be initially used only to create the cargo data between airports. The new passenger demand model will be added later when the concept is tested with cargo.When?
As usual, no fixed ETA or launch date is given. The development of this feature is just one of many things that are being worked (along the daily upkeep of the systems), and the I don't like make promises of dates that might slip by. This is a complicated system with dozens of different smaller components to change and update (all of which affect other parts of the game).
The cargo systems are being tested by a group of our users and while the interface for the cargo features is almost complete there is still work to be done with the new demand system. I will keep you posted!This thread is locked and is reserved for announcements only. Please make all comments to the General forums: http://www.airwaysim.com/forum/index.php/topic,60273.0.html