tlakh/openttd-srnw.org

#+TITLE: OpenTTD Self Regulating Networks
#+DATE: 2024-01-12
[[file:openttd-srnw/srnw_head.png]]
* Prologue
Every other year or so I decide to play a game or ten of
[[https://openttd.org/][OpenTTD]]. Unfortunately I don't remember most of the things I figured
out in the past so I have to start from first principles.
In this case, first principles means reading the [[https://wiki.openttdcoop.org/Main_Page][openttdcoop Wiki]]
[fn::which is quite dense] and watching a bunch of [[https://www.youtube.com/@LugnutsK][LugnutsK]] videos.
* Self Regulating Passenger Network
The idea of a self regulating passenger network is to grow a city and
transport as many passengers out of the city as possible with the
least amount of train orders.

openttdcoop calls it [[http://wiki.openttdcoop.org/Gametype:ICE_SBahn][Gametype:ICE SBahn]] / [[http://wiki.openttdcoop.org/Self-regulating_SBahn][Self-regulating SBahn]].

The idea is to have (SBahn) stations spread throughout the city that
collect passengers. Once a train is fully loaded with passengers, it
drives outside of the city to a transfer (ICE) station and transfers
passengers to a waiting train that then transports the passengers to a
far away city to make money.

We do not want to deal with each station individually but run the
pick-up trains in a loop that automatically visits a station with
a full load of passengers available.

[[file:openttd-srnw/overview.png][file:openttd-srnw/overview_small.png]]

For maximum growth and ease of putting train stations into the city we
are using a 3x3 road grid. A spiral would be even better but it is
annoying to put train stations into a spiral without disrupting the
roads too much and creating dead-ends. Dead-ends are very bad for town
growth.