Human cargo involve two things, People Destinations and People
The destinations are classifications of places, and the people are the sorts of people.
Population Centers (high wealth planets), Employment Centers(low wealth planets), Resort Bases(OSC/etc), Research Bases(Cryer bases, Willard, Planetform, anythign with the word Research.)
VIPs, Vacationers, Passengers, scientists, turists.
The cargo is delienated by what the people will do at their destination.
So, VIPs are on return from Research stations to Resort bases or Population centers.
Vacationers are moving from Employment Centers and Population Centers to Resort Bases
Passengers are moving from Resort Bases and Population Centers to Employment Centers,
Scientists move from Resort Bases and Population Centers to Research Bases.
Turists move from Research bases and Employment Centers to Population Centers.
Note the number of routes this allows for with only four bases:
Such a base allowes for a vibrant human trade in all houses, though it ignores Prisoners, who have something of their own trade routes already, and the same as slaves. PoWs could replace prisoners on battleships, and Refugees start at very specific places, and head to other specfic places, as the story progresses.