After two months of development, version 1.3 is now ready for beta testing! Here's a recap of the new features in the first beta build, from the development notes of the past two months:
Private train track pathfinding
Starting from v1.3 is now possible for different systems of the game to have a different definition of what is an optimal train path. And in the case of the train AI, this definition has been made private to every train. This means the train AI, when evaluating a path, will be able to consider things like the train max speed. It is now making decisions based on the combination of the train and track max speed and the time required to roll down the path, as opposed to just the path length.
New population layer
The new population layer replaces the old population system based on finding road nodes and adding them up inside a grid. The new layer is using actual population density data for the entire world, combined with buildup data. The population layer has a resolution of 250m, and the buildup data is 30m. The game combines both of them to create a single layer.
New elevation layer
A new 90m DEM raster global layer with better coverage than the original DEM layer is now being used as the basis for the elevation layer in the game. This layer will fix the cut out elevation data for high latitudes and many of the errors in other areas of the world.
Administrative regions
In v1.3 NIMBY Rails will provides a new map layer to display the limits of some administrative divisions, from the equivalent of a “province” down to units smaller than a “borough”. I quote these names since the exact definition depends on the country. In OSM terms the game will include the data for admin. regions from level 6 to level 11. This data is for now only used to assign a city name to stations, but in the future it will have more gameplay impact.
User tags
Large builds can have thousands of trains and stations, and hundreds of lines. In order to make managing player built objects easier, and to power future features like conditional signals, a tag and category system is being introduced in v1.3. Players will be able to create an hierarchy of tags, with intermediate tags acting both like a tag and a category. And then assign those tags and categories to player built objects. Object listings then are able to be grouped by tags. For now this system is only enabled for lines, and only in the main line listing in the line editor. As v1.3 gets more mature it will be extended to other objects and listings.
Instanced line drawing
Line drawing in v1.2 and earlier was very memory intensive. In v1.3 a new method for drawing lines (in the graphical sense, not just schedule lines) has been introduced which requires 6x less VRAM. For now this system is only being used for world map features, but during the v1.3 beta series it will also become the default method for track drawing. This will improve rendering performance and lower VRAM usage.
New path signal rules
Path signals are now always a "long" path signals. This means they will check the train path past its next stop, and keep going past any number of stops, until another properly delimiting signal is found, 200km are traced, or a full loop of the train line is completed. Train reservations also apply the same logic. Additionally stopped trains now always assert their track reservation. These change makes path signals more correct and strict, but it might invalidate some existing v1.2 signal layouts.
You can read the full development notes here:
https://carloscarrasco.com/nimby-rails-august-2021/
https://carloscarrasco.com/nimby-rails-september-2021/
This version changes some aspects of the train AI like pathfinding and signal rules, but it does not invalidate the current train state in your save, so it's likely you will see some collision and bottlenecks when loading a v1.2 save, with trains realizing there are better paths and/or red signals. Use interventions to fix these problems. After trains start running anew under the new rules they should go away, but keep in mind the earlier comments about the new signal rules.
If you want to opt into the beta, right click the game in the Steam Library listing, select Properties, then select Betas and select the beta option in the drop down. No password is required. Steam will need to download an additional 5GB of data which corresponds to the new population, elevation and region layers.