It's just a simple resource pack that replaces the shield with a stop sign.
It was technically made for 1.19, but it should work on just about any version that allows custom models in resource packs.
Also, the crafting recipe totally still makes sense, the handle of the stop sign is just extra strong, while the metal part is just extremely weak or you were just very bad at cutting the wood properly, so the planks ended up being wasted.