You don't like federalism much, do you? Btw, states already coordinate voluntarily on things like traffic signs, without there being a central authority. (Tha

You don't like federalism much, do you? Btw, states already coordinate voluntarily on things like traffic signs, without there being a central authority. (That's both true for states in the US, and for different countries around the world. A stop sign looks pretty much nearly the same around the world, without any central authority enforcing that.)