The feature is still under evolution as we get lots of feedback from beta testing, but above you can see a possible - very schematic - user interface presentation we are trying now. (So far the feedback is telling us we need to be clearer about the kind of challenge ahead, so we may still improve the user interface.)
In American Truck Simulator, the majority of cargo terminals has been designed to contain several alternate spots for dropping off trailers. Some are easier to manoeuvre into, some harder. The game will select one of the more difficult spots randomly, and this will be the spot at which you are requested to drop the trailer off during this particular delivery. But a fall-back spot will be also offered for the drivers who don't feel up to the challenge (and there will also be an offer to skip any need for parking the trailer whatsoever, just as it was possible anytime in ETS2). There will also be varying XP rewards based on difficulty of the maneuvers needed to park the truck & trailer in the particular spot.
We believe that this added variety will be appreciated by our fans, it is kind of a mini-game inside the game that breaks up the monotony of deliveries that we had in ETS2. In fact if we do see positive feedback from ATS about it, over time we'd like to come and revisit our existing Euro Truck Simulator 2 cargo depots to allow for more spots for trailer drop-off as well.
If you are not in favor of more UI windows popping up on you and breaking your "flow" through the game, there will be a new entry in Gameplay Options to set your preference there - whether you always prefer to take on the more complex challenge - where the company "really" wants it - or just mostly settle for the easiest back-up unload spots.
Source: blog.scssoft.com