Steam Community :: NIMBY Rails

Devblog for September 2025

Oct 1

Signal scripting is finally in a finished enough state to create new signals! During September a lot of decisions to adjust NimbyScript for general usability were made, and the first 3 examples of real new signaling features were implemented: custom path reservation boundaries, custom signal checks, and the holy grail, path changing signals with no restrictions, fully independent of lines and schedules. Read and see more in the devblog:

https://carloscarrasco.com/nimby-rails-september-2025/

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Version 1.17.11

Aug 5

- Fix: saved file validator was too strict flagging as corrupted some files with salvageable but invalid buildings or signals

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Version 1.17

Jul 31

Version 1.17 has been released

Gameplay wise this is a very small version. It is intended as a public test of the future scripting system, NimbyScript, with the top level logic of path signals and balises now being implemented in NimbyScript rather than the native C++ code. This test was successful in the beta branch and it is now being deployed for all players. NimbyScript will be used for custom signal logic and other functionality in future versions.

But to make this version a little more exciting it includes a couple extra features.

Dynamic braking

Trains are now capable for braking for some dynamic simulation obstacles: (potentially) red signals and other train tails.

When a train is approaching a signal, and it is within braking distance, it will start checking it in advance, and will start braking if it would become a stop signal at that moment in time. To remain compatible with existing saves trains are still capable of unrealistically braking to 0 speed immediately. A future version will expand this capability to also making it possible to reserve the signal in advance (not just checking it) with expanded capabilities in the signal system.

When a train approaches the tail of another train, it is now capable of slowing down and matching the speed of the train in the front. Again to remain compatible the allowed distance for this feature is much shorter than it should be in reality, to reduce the impact on existing saves.

Recolorable UI

It is now possible to change the colors of the UI:

To access the new settings for this feature, go to Options and select Interface.

Alert listing

Alerts can now be viewed in a listing:

All queued alerts are immediately available in the listing, and older alerts are also kept there, past the new alerts and any “missed” alert (shown but not interacted with). There’s a limit of 200 alerts, and they are automatically cleared as new ones are pushed at the front, or you can just clear them manually.

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Version 1.17 is now in the beta branch

Jul 10

Version 1.17 is now ready for testing the beta branch!

Gameplay wise this is a very small version. It is intended as a public test of the future scripting system, NimbyScript, with the top level logic of path signals and balises now being implemented in NimbyScript rather than the native C++ code. If this test is successful, by not introducing instability or performance issues, then future versions of the game will make it possible for players to use NimbyScript for custom signal logic and other functionality. For for now, in 1.17, NimbyScript is read only and the new Control editor is very bare bones.

To make this version a little more exciting it includes a couple extra features, and a few more will be implemented during the beta period.

Recolorable UI

It is now possible to change the colors of the UI:

To access the new settings for this feature, go to Options and select Interface.

Alert listing

Alerts can now be viewed in a listing:

All queued alerts are immediately available in the listing, and older alerts are also kept there, past the new alerts and any “missed” alert (shown but not interacted with). There’s a limit of 200 alerts, and they are automatically cleared as new ones are pushed at the front, or you can just clear them manually.

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Devblog for June 2025

Jun 30

Development in June was focused again on NimbyScript. The language has progressed to the point of being usable, but it's still lacking some basic features. One of these features, memory ownership (think lists, allocating memory, etc) is a very complex subject and it is for now being postponed. 1.17 will feature NimbyScript, but it will be as a non-editable preview, since it's still too immature and any code written in its current state would be invalidated in the future.

But not everything will be a technical test. Two often requested features will also be implemented: recolorable UI and an alert log. Read more in the full devblog:

https://carloscarrasco.com/nimby-rails-june-2025/

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Devblog for May 2025

Jun 1

The past two months have been almost solely focused on developing NimbyScript, the future scripting language for NIMBY Rails. It has been quite hard to get started, with some very lofty goals to achieve, and a lot of reading and experimentation was needed. Read on for the programming nerd adventures in NimbyScript.

WARNING: this is an extremely technical post of little to no interest to most players. NimbyScript is nowehere near finished. Once NimbyScript is ready for being introduced in the game it will get a proper guide. This post is NOT the guide for NimbyScript.

https://carloscarrasco.com/nimby-rails-may-2025/

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Version 1.16.16

Apr 9

- Fix: hang in train simulator when combining stop selection signals, platforms in series with the first platform being occupied, switches in the middle of platforms and trains too long for the stop area and being forced to stop over the switch
- Fix: crash while visualizing pax path routes on the map and at the same time deleting tracks or stations involved in said routes
- Fix: attempting work around for crash in the train info window accounting tab, which cannot be reproduced reliably
- Fix: station editor stop signal pick mode should not display signal buttons if signals are not visible
- Fix: some trains stopped at signals had incorrect signal stop time stats

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Version 1.16

Apr 2

Version 1.16 has been released! This version is a direct continuation of 1.14, with new, optional features in the schedule system for advanced players. And for everybody, this release also marks the first time NIMBY Rails has a proper collision system, so you must now pay attention to train physical size and footprint when designing your track layouts.

Unassigned trains

The schedule system now has the capability of setting trains to become unassigned at the end of an order. This means the train stays in the tracks, stopped, but has no orders and no schedule.

Unassigned trains a have new capability: they can become assigned to any shift, as long as a set of rules apply:

The shift must be currently unassigned
The train must be enabled to run the shift
The current sim time-of-week must match the stopping time (be between arrival and departure times) of a stop in a run in the shift
The current location of the train must also match the platform set of said stop (be on the main or the secondary platform of the stop)

This means that for the first time it is not required for the player to come up with shifts that fill an entire week worth of time. If you plan the unassigned stays properly, you can now make shifts as short as desired, including for single line runs, and let the assignment rules pick the trains as needed.

This feature is strictly opt-in. No changes are made to existing saves, and you must manually set orders to end in unassigned mode. If you don't want to deal with this new feature you don't have to. That being said, since trains can now be authorized to multiple shifts, the interfaces for assigning trains to shift are a little different, but still allow to set 1 train per 1 shift, so you can keep scheduling like you always did.

To learn more about this feature and the exact set of rules which govern it, see this devblog:

https://carloscarrasco.com/nimby-rails-january-2025/

Due to this fundamental change in the scheduling system all trains in existing saves have received an intervention. On loading the game it might take awhile for them to get reassigned to their shifts and to respawn, also you might see some alert spam.

Global, always enabled full 2D train collision

Up until 1.15 the train collision system was based on special cases which only enabled in and around track branches. It was very limited and missed many kinds of collisions, including every collision based on train sizes over parallel tracks, for example. This is not the case anymore in 1.16:

This means you now have to pay attention to these parameters, rather than assuming trains are like ghosts to each other. In general, as long as you kept your parallel tracks with a decent offset and properly signaled your branches, you won't have much trouble. But if you do, path signals are now more capable of checking nearby tracks for potential conflicts, if you need to help them a little with the new "overlap distance" track parameter. This usually needs to be set to the expected maximum train car width for a given track. You will now see the "shaded" area which appears when tracks intersect now also appears when tracks are very close to each other, and that distance corresponds to the "overlap distance". Path signals now check the nearby shaded areas for given train path before signaling the train to pass.

Station-level stop selection signals

Line stop-level secondary stop signals have been replaced with station-level stop selection signals. This means that when you want to designate a signal for the role of being able to select secondary train stops, you must now do so in the station editor. When a train reaches a stop selection signal, and its current path ends on a track platform of a station which includes the signal in its set of stop selection signals, it will be allowed to change its destination stop area. This is the same functionality formerly provided by line stop secondary signals.

Stop selection signals do not define or restrict the set of eligible stop areas in any way; the eligible set of stops areas is always the current line stop set consisting of the main area and secondary areas. This new feature allows to have multiple stop selection signals and to only need to set them up once per station, so you don't need to create multiple line versions just to change the secondary signal anymore.

Deprecating waypoints with secondary "stops"

This redesign has also highlighted some unintended behaviors of secondary stops. In particular secondary stops are not supposed to work for waypoints. This is an oversight in the previous design and it should have never been allowed to exist.

In 1.16 these stops still work and now display a big warning in the line stop editor panel, but in a future version their secondary stops will be ignored. Reproducing their behavior will require using new tools and it won't be an automatic import process.

Queue behavior for advanced stops

A set of new features allows for trains to queue up behind one another while performing a stop, both in regular line operation and when unassigned, without having to set up multiple individual stop points and track segments. The combination of the following features enable this new behavior, although they are also usable for other purposes by themselves.

Advanced stops footprints can now be longer than the reference train. To create an oversized advanced stop, after the first click to set the head point, keep moving the mouse past the end of the line reference footprint. The new stop creation panel now also displays the stop length.
Trains arriving into stops passing by a stop selection signal can now decide to stop behind trains already stopped. This is only possible if the space behind the existing trains is long enough to fully contain the arriving train, plus a margin of roughly 3m. The available space corresponds exactly to the stop footprint, never to the track platform segments, therefore it is only active when the stop is created in advanced mode and when it is oversized.
Path signals can now be restricted to not check past scheduled stops. This is required to enable multiple trains to use the same stop while in regular operation, otherwise the path check would refuse to let the train enter the stop with other trains in its future path. If you use this option make sure your platform exits are properly signaled.
Trains being dispatched are now aware of other trains surrounding them in the stop footprint of the dispatch being considered, and will only accept the dispatch if the footprint between the train and the stop head point is free of other trains. This enables dispatching to only pick trains at the front of a queue, as long as the picker order stop is pointing in the correct direction. In particular, if you are using this feature with dead end depot tracks, the arrival stop must point towards the track dead end, and the departure stop must point towards the linked end.
All stop vs train and stop vs stop matching is now done based on the precise footprint of line stops or trains over the tracks. The old rules based on the train/stop heads, track segments and directions are not used anymore.

Run and line duration can now go down to 10s

Minimum run duration and line duration is now 10s. In exchange shifts cannot have more than 2520 runs (equivalent to filling the week with 4m runs). If this limit is reached the last run of a shift will be marked as not continuing and the rest of the orders will be ignored. Existing schedules using lines with a native duration of under 5m which were depending on the automatic padding and distribution of 5m duration might need adjusting. For example, a common error is to have your depot orders set to max number of repeats. Make sure you disable repeating runs for single stop depot orders.

Runs generated for autorun lines are sill limited to a minimum of 5 minutes, and this time is now padded, not distributed. If a line with a duration of under 5m is wanted to run in auto run mode with distributed time, please use the line timing options to do so.

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Version 1.16 is now in the beta branch

Mar 7

Version 1.16 is now ready for testing in the beta branch! This version is a direct continuation of 1.14, with new, optional features in the schedule system for advanced players. And for everybody, this release also marks the first time NIMBY Rails has a proper collision system, so you must now pay attention to train physical size and footprint when designing your track layouts.

Unassigned trains

The schedule system now has the capability of setting trains to become unassigned at the end of an order. This means the train stays in the tracks, stopped, but has no orders and no schedule.

What is the use of this seemingly useless feature? Unassigned trains a have huge, new capability: they can become assigned to any shift, as long as a set of (strict) rules apply. Basically, if an unassigned train is located on the right platform at the right time, it can become assigned to any shift schedule to service said platform at said time, as long as no other train is assigned to the shift, and the train is authorized to run it. This also means that for the first time it is not required for the player to come up with shifts that fill an entire week worth of time. If you plan the unassigned stays properly, you can now make shifts as short as desired, including for single line runs, and let the assignment rules pick the trains as needed.

This feature is strictly opt-in. No changes are made to existing saves, and you must manually set orders to end in unassigned mode. If you don't want to deal with this new feature you don't have to. That being said, since trains can now be authorized to multiple shifts, the interfaces for assigning trains to shift are a little different, but still allow to set 1 train per 1 shift, so you can keep scheduling like you always did.

To learn more about this feature and the exact set of rules which govern it, see this devblog:

https://carloscarrasco.com/nimby-rails-january-2025/

Global, always enabled full 2D train collision

Up until 1.15 the train collision system was based on special cases which only enabled in and around track branches. It was very limited and missed many kinds of collisions, including every collision based on train sizes over parallel tracks, for example. This is not the case anymore in 1.16:

This means you now have to pay attention to these parameters, rather than assuming trains are like ghosts to each other. In general, as long as you kept your parallel tracks with a decent offset and properly signaled your branches, you won't have much trouble. But if you do, path signals are now more capable of checking nearby tracks for potential conflicts, if you need to help them a little with the new "overlap distance" track parameter. This usually needs to be set to the expected maximum train car width for a given track. You will now see the "shaded" area which appears when tracks intersect now also appears when tracks are very close to each other, and that distance corresponds to the "overlap distance". Path signals now check the nearby shaded areas for given train path before signaling the train to pass.

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Devblog for February 2025

Mar 2

Work in 1.16 has continued in the month of February. Stacked train stops (sequences of stops for the same platform(s)) were not fully compatible with the new train logic in 1.16 and have been reviewed with a new, clearer set of rules which avoids some pitfalls. Train collision has been finally overhauled with a new system that performs real geometric intersection tests. And a new, very major technical capability for the game is introduced at the end of the post, but its release will have to wait for a future version. Read about it in the dev blog post:

https://carloscarrasco.com/nimby-rails-february-2025/

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