Nightly build as of 2017-06-29 05:11
I have encountered a reproducable bug and created a savegame demonstrating this.
The vehicles do not leave enough time for the vehicle ahead to reverse and return backwards, creating an immediate deadlock. While randomly present a few builds prior, it has seemed to manifest itself in the game as of this week.
To recreate, start at least two convoys in either depot and let them run their schedule.
https://drive.google.com/open?id=0B6xweGGa9eNrUnRaOFNFNHU2NE0
Thank you for the report; I think that I have managed to fix this; would you be able to re-test? I should be most grateful.
Bug has been fixed, thank you very much James!