Factorio Forums

Observed behaviour:
If you currently drive a two-headed train (or a single-headed train backwards) in manual mode and switch on automatic mode, the train instantly drops to zero speed if the new destination is in the opposite direction.
Expected behaviour:
The train should decelerate/break regularly to a full-stop, then start driving in the opposite direction automatically.

I’ve created a sandbox game to show the issue.

1. Create a player character, if none is created.
2. Enter the end of the train having three locomotives, Open the train GUI
3. Accelerate the train, it should accelerate quickly
4. Switch from manual driving mode to automatic mode. The train instantly drops to zero speed.

PS: I am not able to respond in the next days.

I think this has been the case for a while, and might partially be related to the fact that the train doesn't know what way to take at upcoming junctions (between it and the braking stop location).

This is kind of different from mining a train stop which is the next stop on a schedule.

If the train moves backwards, is switched to automatic mode and the pathfinder finds a path from the current position to the destination leading in the opposite direction, it can always do a normal break stop, then accelerate in that direction.

This is true, because moving backwards relative to the target direction does not invalidate path choices by passing them. Therefore, if there is a valid path, it is not invalidated by driving backwards further during the break process.
(This may be breakable by deliberate signal placement…)


But if it is a design decision, I’m fine with it.