Barely made a random traffic system... But found it very low efficiency to set the road template....

Hi
I’m new to UE4. There is a problem I’ve been thinking for a long time. I checked many tutorials but I can’t find a better solution. I think I might get some help here.
This thread might looks long, but most of them are just pictures to explain the problem.
Thanks for your time, and I apology for my poor English in advance 0_0

Brief:
I’m trying to make a traffic system, which includes:
----Auto generate different Roads[done]
----For each type of Road, there should be corresponding RoadPoints[Problem here]
----Randomly generate Vehicle, and the Vehicle will automatically find the closest RoadPoints [done]
----After Reaching each **RoadPoints, **Vehicle will go after the [NextPoints] or [NextAlterPoints] or [NextStopPoints], As the ,[green], line showed in the picture below [done]

Problem here is I can’t find a way to set RoadPoints in Road effectively

Still in the picture below, I selected my RoadPoints Actor. It’s a BP Actor that generate an arrow to every RoadPoints in the [NextPoints] list.
It’s done in the Construction Script, so I can easily pick up a RoadPoints or modify its position. And I can see the result after each action.
So far, it’s fine and convenient to connect** RoadPoints** in a scene (permanent level)

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Then I made several types of Road Actor for random spawning, and I try to attach the RoadPoints to the Road as ChildActor. Showed as picture below

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Then the problem here is, for each RoadPoints child actor, I can’t select RoadPoints child actor as [NextPoints]. Not like what I can do when I put the RoadPoints into a scene (permanent level)

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So to connect these RoadPoints child actor, I set the [NextPoints] in the Construction Script in each Road Actor.
As the picture showed below, it is very complicated(4x picture for one Road Actor)

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After the settings above, and the condition that I need to compile RoadPoints after compile Road, I can get the result that is a Road with RoadPoints connections preview able.

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I can barely achieve the system now, but I think it is too low efficiency, and hard to make changes

The whole big question for me is IF/HOW I can do better to attach the RoadPoints to the Road and connect them easily.
I think it’s a same question about how to attach a child actor to another actor and set connection among them

Of course I’m not asking for a full solution. If you have any experience or thoughts on this, please, just let me know
It’s OK for me to throw everything away and redo from beginning.

PS:
For this traffic system, I need many Road types like 2-lane Road, 4-lane Road, 6-lane Road, cross Road, Arc Road, or some roads with strange shape, so I think a flexible RoadPoints with preview is a must have.

I tried to use BP actor component instead of BP child actor. It can save the process of cast to, but BP actor component do not have a Construction Script and make the preview more complicated. I still do not know how to find all my BP actor component under one actor and do something to them.
I also tried to put a ArrowComponent or a box to replace the RoadPoints actor, but I can’t find a place to set data structure like [NextPoints] [NextAlterPoints] [NextStopPoints], seems to be worse than a BP actor component
Or, is it possible to select several Actor from the scene and make it an new Actor? Like what you can do to create a prefab in Unity. If so, I don’t have to attach them, I just need to spawn two actors together.

Anyway, thank you for your reading!! Any thoughts please let me know.