The question is, are the clumps at the entrance new people or old people that haven't moved far.
The problem with your idea tiger is that if it isn't a closed loop you can only have one vehicle that goes back and forth. NEVER MIND, just realised you did do loops .. but I will leave this here any way rofl.
And once they start queueing they don't leave the queue until they have got on the vehicle.
The below or something similar could work, but, be aware that they will turn around if there are no animals or amenities within a certain range of the entrance ( or access to them like transport ) so depending on how far out you want those three initial stations to be, you might need something to shuffle them towards them, like exhibits, amenities etc. For example: I didn't put it on there but, you could put a walkthrough exhibit as part of the path that goes from entrance to the north station. I've used that tactic as a trick to move them further forward before they see anything else good rofl. And of course a walkthrough exhibit is a good money maker. It's a pity we don't have more options for them as I can't use them in all my alphabet zoos rofl.
All stations need access to the entrance via path as staff don't use stations to move from A to B and will need to get around. And guests need path options to get around and view animals if the transport queue is full.
And, check the peoples views on transport prices. They will tell you if you need to up the prices by the way they respond to them. So up it until they stop praising how cheap it is.
Depending on how expansive you make each transport route, you can add more stations, more pathing, more amenities, more animals etc for each station access area. Just make sure that the staff have a path access to everywhere they need to get to and the entrance. Guests just need alternatives if they can't join the queue even if it's a path to the next station or habitat/exhibit viewing point.
And with access paths in the three directions east, west, north you can create similar networks to slowly move them round the zoo.
Now, you could start with one way routes with the one vehicle going back and forth until you have money to expand the area further, but then you will need to stop the transport ( kicking people off the queue - maybe make them unhappy and leave? Never tried this so don't know ) and adjust the transport route.
Or you could make each transport route smaller and more of them with just 2 stations to shuffle the guests around the zoo.
Of course I haven't tried this out myself as I almost always have a chunk of stuff right near the entrance to get them spending so I can expand. But, you can always expand out later and
remodel as you expand. Which I do plan to do for my bigger alphabet zoos ( that have all their animals ) at some point.
I also found out recently that terrain painting doesn't seem to cost money, so you can always plan the areas out, and slowly build out as you grow. I've been trying that on one of my xth zoo rebuilds I've been doing recently.