Well you just said it. The developers determine the speed limit. They can’t really change it or anything like that. Additionally, it’s part of the traffic code so it can actually he enforced. I don’t try to be mean here but everyone enforces state law, some people enforce county law, but it’s super limited on who enforces municipal law since people honestly don’t know what laws apply. You won’t see a cop try to drag out a traffic stop by going on a 10 minute hunt to find a municipal law just to find that the municipality changed Trellos recently and nothing is valid on the Trello that is linked. Lastly, I’m unsure how legal municipal laws are tbh.
C.V.VIII states, …“and no state entity shall be responsible for enforcing any ordinance of an inferior government unless outlined by state law.” I interpret that as, you aren’t allowed to enforce municipal laws, unless granted by the state. The reason I say that is because there isn’t a constitutional amendment that says “hey, this is how counties are established” instead it’s C.I.III “Congress shall have legislative jurisdiction over the entire State of Firestone and its subordinate entities, including counties and municipalities.”. Again, this amendment talks about how congress can override action from the counties, but it doesn’t say anything about what powers the county can possess and how they are established. If anything, C.I.I is clear in saying, “All legislative powers granted herein shall be vested in a Congress of the State of Firestone, the sole state legislature.”. Which I interpret it as saying, there shall be only one sole legislature that creates laws in the State of Firestone and that is Congress. And if that isn’t enough evidence, A Bill to Save the Stapleton County Government which establishes the County doesn’t even give it power to establish municipalities. In fact, there is no state law that even talks about municipalities.
But hey, that’s how I interpret it. Myself and @1superchris2 drafted up a county amendment for the constitution on how everything is to be regulated, including municipalities, but I guess it got lost somewhere. 
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