Did anyone notice, during the last test, that patches of dirt had been almost uniformly turned into dirtless holes? I think I know why.
Several street projects required chunks of dirt. The only way you get them is to use a shovel to dig into a patch of dirt. This gives you a few chucks of dirt, and leaves the patch as a dirtless hole.
Several street projects that I joined were stuck waiting for a large number of chucks of dirt. A dozen people (or more) had quickly contributed everything needed to the project, up to the chunks of dirt. Then they just stood there, waiting for someone to bring dirt. A few people scoured the adjoining regions for patches and (finally!) brought back enough dirt. And then, the waiting zombies ground and meditated and did whatever in order to complete the street.
So let me condense this: once I got to a street project, it was waiting for dirt. It could wait like that for hours. Once the dirt arrived, the project would be completed in seconds.
So I think there's a math problem here, and an ecology problem.
The math problem is: given the number of dirt chunks needed for the number of open street projects, and given the refresh rate of dirt patches in reasonably nearly regions, how long does it take to complete a street project? How does that compare to the total time to complete the project? If the former is, as I suspect, almost the same as the latter, then every street project will, on average, always be waiting for dirt. That's boring and should be fixed.
Perhaps more importantly, there is an ecological problem. Dirt patches only exist in regions in which they have not been planted, that is, regions in which trees are not growing in them. Once a tree is growing in a patch, the only way (I think?) that it reverts to a treeless patch is if the tree is not sufficiently petted and watered. But there is a strong incentive for lower-level players to pet and water every tree in sight, so that's not going to happen.
So there will, it seems, be fewer and fewer patches without trees. And folks who want to contribute to street projects will become more and more greedy in digging dirt from those tiny few patches that remain.
So, dear devs, you seem to have created a conflict that will ultimately be resolved on the side of the tree planters and limit the creation of new regions. I would suggest that it would be clever if the resources required to create new regions were renewable, which patches are, ultimately, not.