However it can also be used to run an activity (or part of it, as it is possible to turn on and off autopilot mode at runtime) as a trainspotter (or a visitor within the cab).
Autopilot mode is now committed since release 2683.
Autopilot mode is enabled with the related checkbox in the Experimental Options. It is active only in activity mode (no explorer, no timetable mode).
Starting the game with any activity you are in player driving mode. If you press Alt-A, you enter the autopilot mode: you are in the loco's cabview with the train moving autonomously accordingly to path and station stops and of course respecting speed limits and signals. You still have control over horn, bell, lights, doors, and some other controls that do not affect train running. The main levers are controlled by the autopilot mode, and most indications are correct. I havent' yet blocked influence of all keypresses (it is a lengthy thing), so I take no responsibility if you to try to enter commands against the autonomous movement of the train.
When in player driven mode you can also change cab or direction. However, if you return to autopilot mode, you must be on the train's path; other cases are not yet managed. When in player driven mode you can also switch to manual, but before returning to autopilot mode you must first return to auto mode.
I have made my best to synchronize station stops, waiting points and reverse points in the two modes.
Cars can be uncoupled also in autopilot mode (but check that the train will stop enough time, else better pass to player driven mode). A static consist can also be coupled in autopilot mode.
Request to clear signal (TAB) works in the sense that the signal opens. However in autopilot mode by the moment the train stops. You have to pass to player driven mode, to pass the signal and then you can return to autopilot mode.
Revised 5/12/14