I"m guessing that sign is only valid on Ohio Street, in Houston, Texas
Ohio St
Houston, TX 77047
(Just kidding, ... funny sign)
That sign came from here:
http://www.compliancesigns.com/NHE-5332 ... Ohio.shtml" onclick="window.open(this.href);return false;
And I agree, CHLs are "authorized by law", even if that sign held water, which it doesn't.