I was kind of thinking of the following flow. The big issue is that you'd have exit traffic crossing the tram line in the red circled area. You'd also have some crossings for people going into and out of medical parking. And of course the biggest issue is that people parking on the north (bottom) side have to go the long way around. Let me know if I've missed something else, I appreciate all input and constructive criticism. I'm not really proposing this, it's just an interesting topological puzzle.You still get merges.
How about one giant, one-way, non-branching labyrinth?! No mergers, no cross-overs. Just get everyone to drive the entire area of the whole parking lot in a zigzagging conga line.