https://mega.nz/file/BbID3YTA#2m6GnhzmfA5MIP5AuebvhhB1bh-2C8EnJlVzfdfeqQE
If two vehicles pass through a junction and reach the "end of signalling" after another vehicle has just passed it, it will slow to 1km/h and slowly pass over the tile until it has passed the tile, at which point it will resume to normal drive by sight.
Thank you for your report and apologies for the delay. I am afraid that I am having some trouble reproducing this: I can see the anomalous positions at the beginning (but the problem has already occurred by this point and this cannot be reproduced from this), but, for however long that I run it, I cannot get this state to recur. Can you give any more detail on how you can generate an initial occurrence of this using this saved game? Thank you.
Edit: Specifically, are you able to upload a saved game a few seconds before this reliably occurs?