The Manual on Uniform Traffic Control Devices for Streets and Highways. The MUTSET was first published in 1967 to stop things like NY using yellow stop signs. It is like the model traffic code in that the states have input. This is not someone having a brain storm at the DOT..
Who publishes the MUTSET? Washington? Or some professional body with too much time on its hands and no responsibility for outcomes?
Except that this move was NOT approved by the cities. Many states objected to this change yet the feds are forcing it anyway.