Version 1.12 is now ready for testing in the Steam beta branch. This version completely changes the way pax are spawned and the way they pick their destinations.



In 1.12 pax are spawned on specific geographical points, rather than by picking a station. And their destinations are also points in the map. Only after these points have been established are stations also picked, based on which stations can be reached from these points. Geographical points are picked based on population density. For now there is no visualization of these points so pax still just appear inside their origin stations, but the consequences of this previous step are very directly noticeable, specially when enabling the new "best path" mode.

Additionally, the way demand is generated has also changed. In 1.11 and earlier the achievable pax spawn rate of a given station was fixed, based on the station coverage. In 1.12 the pax rate depends both the population density around a station, and the reachable population from the station, subject to the distance demand curve. This means that opening more destinations in your network does not cut down on the desirability of other destinations, it will just make existing stations generate more pax (always in proportion to the demand curves).



Since pax now spawn on map coordinates, and they have a (player configurable, limited) capability of picking their origin and destination stations, it does not make sense to divide station coverage like in 1.11. In 1.12 station coverages can overlap:


Players can now create special sign-like buildings which add some amount of population to a point in the map:

These signs count as population points, just like the built-in population texture. They can be used to for example liven up areas which see high demand in real life but have low population, like airports.



To make the new POI feature even more powerful, it is possible pick a different demand curve for each POI. This allows to define POIs which have a different time based demand curve, for example a stadium only being active for a few hours a week, but having an outsized effect on its nearby stations by combining it with a large population value. Or making the distance demand curve of an airport much less dependent on the distance, compared to the default curve.

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For more information check the blog posts:

https://carloscarrasco.com/nimby-rails-february-2024/

https://carloscarrasco.com/nimby-rails-march-2024/

https://carloscarrasco.com/nimby-rails-april-2024/

Work continued with the new pax demand generation system in 1.12, with the introduction of multiple custom demand curves and player defined POIs. In 1.12 it will be possible for players to define custom time based and distance based pax demand curves, to control pax spawn and pax picking of destinations. These curves can alter the built-in population layer, and they can also alter a new kind of game object: points of interest. These POIs will be a special kind of building players can place anywhere on the map, and then assign a population value and a demand curve to them. They then become part of the pax generation for all the stations covering them, and also an attractor for pax demand from other stations. Check the blog post for more details and other new features:

https://carloscarrasco.com/nimby-rails-march-2024/

February saw the final releases of the 1.11 beta series, and the start of internal experimentation and development for 1.12. I originally intended for 1.11 to also feature pax generation changes, but the scope of the changes became too big to just be a "plus one more thing" feature during a beta period, so it has now been reassigned as the major feature of 1.12.

Work on the new pax generation system has begun, with many experiments done in February, to put some ideas to the test and see which ones are practical and which ones are not. The guiding principle is to try to model natural demand for pax trips, and then adapt the designs to the reality of a real time game. Solutions have been found for some the challenges of adapting this idea to the game, but a lot of work still remains to be done.

https://carloscarrasco.com/nimby-rails-february-2024/

Version 1.11 is now the default Steam version! This version contains only few user-visible changes, with the bulk of the work focused on optimizing the game sim to extract as much performance as possible from 4+ core CPUs. There's also pax pathfind improvements and new features, like board and disembark -only line stops.



In 1.11 the game simulation and the game UI can now run fully independent from each other. This boosts the game simulation speed by potentially a large margin, depending on how large your save is (and for users with less powerful GPUs, on how complex your on-screen buildup is). Since the game simulation was already massively parallel, this increases the CPU usage of the game. Faster sim = more CPU usage. If you prefer the game making less use of your CPU, in 1.11 it is also possible to limit this capability down to just 2 sim threads, with the corresponding sim performance hit.



Board only and disembark only line stops are now possible. Although not super realistic, it is useful to keep local pax from boarding long distance lines making multiple stops in a large city, for example. Or to make sure large capacity lines only empty their trains in some selected, less busy stations. Factorio or a human transit simulation? You decide!

Pax pathfinding can now consider a pax staying inside a train for more than 2 train runs. This limit has been in the game since 1.5 and it is now finally removed. The pax pathfinder can now plan a path leg which keeps the pax inside the train until the train starts a technical line or an already visited station appears (not just the boarding station), whichever comes first, over any amount of train runs, including an entire week worth of them.

"Figure 8" or "pretzel" shape lines are now better supported. These lines, in conjunction with single line stations, have had limited support in the pax pathfinder. In 1.11 the game is able to detect more cases of a transfer station, including cases of a line crossing over itself on the same station, or a common looking line having a single direction loop in one end (in this case, the station(s) just before the loop are marked as transfer). This means there are now some cases where pax can disembark in a station and pick a train of the same line, to avoid the loop part of a "figure 8" line for example.

Finally, it is now possible to restrict pax from boarding a train if they plan to ride it for a too short time. For example, if you have a long distance line making a couple of stops in a big city, and want to forbid local pax from using it like a subway between the two stations, you can set a minimum stay time in these stops. Pax will stop considering them as valid legs in their trips if the ride time is under your setting.


I've written this a bunch of times over the years already, but the new version contains major multiplayer fixes and optimizations. This time I'm confident enough that I've enabled up to 100x shared sim speed and made it the default setting, and feedback from the beta period has been positive. Give it a try if you are a multiplayer fan.



A new option in the company panel now allows to change into a new time zone mode: Approximate. This mode uses a real world time zone map, instead of the previous simplified rule of having one time zone every 15 degrees of longitude. It's still called "approximate" because in order to keep performance from diving, it is a rasterized map with a resolution of around 5km, so locations within a 5km border of a time zone might display the wrong one. Still it's a huge improvement over the previous system.



It is now possible to change what time of day the game accounting considers as the start of day, relative to UTC 0. So for example, if your save is mostly built up in the USA east coast, you might want to consider changing accounting start time to -5h, so it tracks the USA Eastern time zone.

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For a more detailed and technical look into what's in 1.11, check the devblogs:

https://carloscarrasco.com/nimby-rails-november-2023/

https://carloscarrasco.com/nimby-rails-december-2023/

https://carloscarrasco.com/nimby-rails-january-2024/

Version 1.11 is now available in the Steam beta branch! This version contains only few user-visible changes, with the bulk of the work focused on optimizing the game sim to extract as much performance as possible from 4+ core CPUs. There's also pax pathfind improvements and new features, like board and disembark -only line stops.



In 1.11 the game simulation and the game UI can now run fully independent from each other. This boosts the game simulation speed by potentially a large margin, depending on how large your save is (and for users with less powerful GPUs, on how complex your on-screen buildup is). Since the game simulation was already massively parallel, this increases the CPU usage of the game. Faster sim = more CPU usage. If you prefer the game making less use of your CPU, in 1.11 it is also possible to limit this capability down to just 2 sim threads, with the corresponding sim performance hit.



Board only and disembark only line stops are now possible. Although not super realistic, it is useful to keep local pax from boarding long distance lines making multiple stops in a large city, for example. Or to make sure large capacity lines only empty their trains in some selected, less busy stations. Factorio or a human transit simulation? You decide!

Pax pathfinding can now consider a pax staying inside a train for more than 2 train runs. This limit has been in the game since 1.5 and it is now finally removed. The pax pathfinder can now plan a path leg which keeps the pax inside the train until the train starts a technical line or an already visited station appears (not just the boarding station), whichever comes first, over any amount of train runs, including an entire week worth of them.

"Figure 8" or "pretzel" shape lines are now better supported. These lines, in conjunction with single line stations, have had limited support in the pax pathfinder. In 1.11 the game is able to detect more cases of a transfer station, including cases of a line crossing over itself on the same station, or a common looking line having a single direction loop in one end (in this case, the station(s) just before the loop are marked as transfer). This means there are now some cases where pax can disembark in a station and pick a train of the same line, to avoid the loop part of a "figure 8" line for example.



I've written this a bunch of times over the years already, but the new version contains major multiplayer fixes and optimzations. This time I'm confident enough that I've enabled up to 100x shared sim speed and made it the default setting (famous last words?). If you are a multiplayer fan give the beta a test.

---
For a more detailed and technical look into what's in 1.11, check the devblogs:

https://carloscarrasco.com/nimby-rails-november-2023/

https://carloscarrasco.com/nimby-rails-december-2023/

Work continued in December to implement major optimizations, but some diminishing returns were starting to hit, so I started a partial multiplayer rewrite to try to fix the many issues it currently has. I discarded large swats of code, old attempts at fixing shared mode and editor synchronization. It's now looking much better, at least on my end, so we will see how it goes when the beta goes public. I then took some holidays to think about where to go next with 1.11. The main idea I had for the release was not working out, so I implemented some small features and will consider making a release sooner than later.

https://carloscarrasco.com/nimby-rails-december-2023/

Time flies when you are deep into optimization programming, and that's how November went by. The remaining roadmap items are very CPU intensive, so the game needs to extract more performance from the CPU cores. A very deep rearchitecture is ongoing, with a variety of strategies like database-like transactions and triple buffering game state. As a result the UI and the game sim are now fully asynchronous, removing a large pause from the game sim, letting it run for a longer in time on the CPU cores.

November was definitely a technical maneuvers kind of line, maybe December will return to more regular service.

https://carloscarrasco.com/nimby-rails-november-2023/

- Fix: mangled text labels in some map areas
- Fix: remove most duplicate results from the search engine
- Fix: some low density population areas were not adding population coverage to stations
- Fix: cancelling a track link in the track editor for tracks with the "keep straight" flag enabled could sometimes cause sibling tracks to not update their shapes

Version 1.10 is now in the default game version. The focus of 1.10 is an updated OpenStreetMap layer, plus updates to some of the other map layers. This means a full redownload of the game is required when updating to version 1.10.

In addition to the new map data, a new map rendering engine has also been implemented, This new engine is improved in all aspects. For example it has much higher hillsahding quality:

A new style has been implemented for OSM data, with better colors and less noisy textures:

It is also enabled for map style mods, and you can already find some community provided mods in the Steam Workshop to both modify the base map and to display new information in the underlying OSM database. Read the devblogs for August, September and October for all the details:

https://carloscarrasco.com/nimby-rails-august-2023/

https://carloscarrasco.com/nimby-rails-september-2023/

https://carloscarrasco.com/nimby-rails-october-2023/