On Aug 19, 2020, at 6:52 AM, xxxxxx@gmail.com wrote:

That (and some other stuff involving SPA in Traveller) seems to suggest a much larger/more involved entity than a traditional modern port authority. 

The SPA has hands in more pies and across a much larger scale of space and scope than modern equivalents to the point they likely are closer to a fulsome Imperial goverment Bureau than a local or even national port authority in our world.

Yes, they are a key piece of the Imperium’s power. This is part and parcel of that whole “Ruling the space between the Stars” thing, and another reason the Imperium has such a large Navy. (also how the Imperium *affords* such a large Navy…)

It is also directly lifted from history and places like the Trading ports established by the British, Portugese and Dutch around Asia.  See Nagasaki https://en.wikipedia.org/wiki/Portuguese_Nagasaki or Macau https://en.wikipedia.org/wiki/Macau

That is the historical equivalent of a SPA Starport.

This is not to say that there are not starports that AREN’T managed by the SPA.