The 55 MPH Speed Limit Will Be Enforced
If I get a speeding ticket, can I just argue that the sign's use of the future tense clearly indicates the lowered speed limit doesn't apply yet?
That's why I formulated my silly example the way I did, but I guess I was being too subtle.
And generally don't those say "Strictly Enforced"? The implication being that they will bust you even for 56 in a 55 (generally, again, because it's a construction zone).
Finally, I seem to remember that the issue is that California has a relatively (couple years old) new law that a speed limit must demonstrate that it is at the 80% point or has an explicitly documented exception or it's challengable. Presumably, these signs fall into the "explicitly documented exception" category.