Of course not. Everyone would ignore it, just as they ignore speed limit signs and stop signs.
Maybe this one will actually affect a driver, since they could imagine the whopper lawsuit if they hit the autistic child. I've never seen a sign like this, but I've seen "Deaf Child" signs. The principle is that a deaf or autistic child will not respond to the sound of a car horn.
and the other presumed principal is that most drivers will toot the horn and figure that's warning enough for any child, not following up to see if the child continues to chase the ball into the street but proceeding on without regard for the child's response.
Right? That's the only scenario under which a sign like that makes sense; unless, of course, tweaking the emotions of the driver somehow makes him better able to avoid running children over.
I’ve got a cousin who lives in a “Deaf Child Area”. I always activate my flashing stobe light when driving through this area.
Got another cousin who lives in a “Bi-Polar Victim” area. I have extra meds ready.
Got another friend who lives in a “Schizophrenic Affected Person” area. First I drive one way, then I drive another.
Got a brother who lives in a “Beer Addled NASCAR Fan” area. I always take an extra six pack and a bag of pork rinds when I go there.
My sister lives in a “Sensitive, Progressive, Environmentally Concerned, Gentle, Anti-Bush War Peacenik” neighborhood, I always take an extra gun and some Claymores when I go there.