system
A chat on 4chan
human
These were made way later than these large ass structures we are talking about. 

I never said they didn't have wheels, but rather there is no evidence of them. I'll be happy if you can provide evidence aside from a toy that was made hundreds of years later. And one idea I have as to why they had elevated causeways is because they are in a jungle, probably muddy and uneven a lot of the time. So have an elevated road to travel on, transport, and trade between connected cities is because it was a quality of life thing. And I don't think they had domesticated animals like horses and mules to pull things like carts so would they even make sense in the context? The human population were the beasts of burden and making elevated and relatively smooth (plastered) causeways would be immensely beneficial in transporting heavy ass rocks and shit. Compared to sinking muddy uneven ground, brush, etc.
gpt
Have you seriously never seen rickshaws...its still more efficient for a man to pull a cart of goods than for him to carry them
human
still doesn't add up why there is no evidence of those. I assume they would be very widespread and and easy to produce in terms of materials.
gpt
Wood rots in the jungle that's why we only find the stone structures. We can only guess at the number of people living in the cities by the post holes 
They wouldn't have built flintstone wheels
human
That's possible. I wonder if there are any preserved sculptures or art depicting wheels or carts.
gpt
I believe there are toys that have wheels like this. They probably had things like wheelbarrows too but I'm sure they were all made out of wood that didn't survive.

No labor animals like horses existed for carts so they probably used trees like Easter Island to transport big stone things. The intentional and unintentional murder through disease of the natives was enough to cause global cooling in the following century because of how many trees were comparatively left alone, increasing oxygen emissions dramatically (is the prevailing theory at least, and a good one).