A Traffic Sign for John C. Calhoun

New traffic signs have appeared on the drive to my son’s school that perplex me and have me thinking of John C. Calhoun.

1) Why so many words/pictures?
As I count it, there are eight words/pictures in the above sign. That’s a lot for a driver in a moving car to absorb while he or she is driving. And reading down, you have to be able to shift from words (state law) to pictures (yield sign) to words (to) to pictures (pedestrian sign) to words (within crosswalk) to pictures (exclamation sign).

Is having such a long message really more effective than these traditional alternatives:
Of course, the proliferation of words in the new sign might be what makes it more effective. Drivers slow down to read all of the words/symbols. Maybe this is an example where verbosity saves lives.
But I doubt it. What’s more, I doubt that this has been tested empirically. I’d love to meet its tailor. We’ll send some Freakonomics schwag to the first reader who can send an example of a traffic sign with the most words/symbols directed toward moving vehicular traffic with an injunctive message. I’ve encountered longer parking signs. I’ve also encountered longer non-injunctive highway signs that give information about the next exit. But I can’t remember seeing a longer “Thou Shall (Not)” sign.
2) Why “State Law”?
Is it really necessary to tell us that the obligation to yield for pedestrians comes from state law? I understand that the government has a monopoly on putting up these traffic signs. Speed limits don’t incorporate the source of the injunction to drive less than 35 miles an hour. Would the signs be less effective if they excised these two words? And by emphasizing them, do these signs make other traffic injunctions less authoritative?
3) Why “State”?
Here’s a question for Steven Pinker. Why would the sign sound wrong if we left out the adjective “state”? Seatbelt billboards often say that wearing seatbelts is “not just a good idea, it’s the law.” They don’t mention the source of the law. The Miranda warning doesn’t say, “You have a constitutional right to an attorney.” Or “You have a right to an attorney that was dreamed up by activist judges.” Is the emphasis necessary because people would not abide by a traffic rule that was merely a federal (or municipal) law? This is a sign that only an advocate of state rights über alles, like John C. Calhoun, could love.