From what I have seen, the empire state building for example, and many others has limited dock space and I have never seen a ups trailer in there. I have seen ups trucks parked all day in one spot in that vicinity bringing packages to and from the truck with an overloaded dolly- the type of hand truck that converts to a four wheeler unit- I believe they are called by the brand name -gemini??? I have also seen transfers of packages from these "all day parked trucks" to other ups package cars that pull up time to time and then take off once the transfer is complete.
I have never seen a ups trailer in any loading dock of any building in manhattan. Loading dock space is limited and times to occupy them are limited as well. Many truck drivers unload their contents onto the sidewalk and bring them into the building with handtrucks and dollies as opposed to waiting 2 hours for a space to open up on a loading dock
I often see ups package cars plastered with parking ticket violation tickets. The common practice for big companies is that they fight the ones that are fightable, and the ones they can't can't -fire hydrant, bus stop, etc are thrown into a big pile so to speak and the total dollar amount of the tickets are reduced in negotiation with the nyc dept of finance. I assume ups follows this practice.
I have been at the ups 43rd streer facility in nyc as a feeder driver but have had not had the "pleasure" of using the upper levels although from what I heard some feeder drivers have had the pleasure and as a result took out a water pipe as their trailers were moving too fast and bounced upwards and bumped the overhead pipe. I believe the pipe has been relocated, but don't know for sure.
There is also another ups facility in lower manhattan on houston street that is street level and seemingly and probably quite a big larger than the one on 43rd street , the one someone saw near the Intrepid. That is a much easier place to work out of in terms of moving trailers and the layout is much more similar to many other centers .