Does Mass Transit lower high wealth land value?
Solution 1:
The answer, in fact, is yes.
Upon very close inspection, I noticed that bus stops/stations, streetcar stops/stations, train stations, and ship terminals ALL are detrimental to the highest wealth land value. This is not made clear at all by any tooltip in the game. Each of the mass transit options indicate that they transport low- and medium-wealth sims around the city, but not that they have negative effects on the high wealth populace. I had just assumed that the high wealth sims simply would not use the system.
To test this, I left the land value data layer open and removed bus stops and streetcar stops in my high wealth district. With each sign or stop removed, the high wealth coloring filled in completely where it had been spotty. If I added back the stop, it became spotty again.
Also, when checking the happiness of buildings around the stops, sometimes they would indicate "undesirable" neighbors. Once the stop was removed, that complaint went away.
This does NOT apply to school bus stops, only to mass transit stops.