Seeing the actual ordinance, I agree with you.
Especially since this is the rest of that particular ordinance.
B. Any structure or device erected or maintained contrary to the provisions of this section is a public nuisance and the Director of Engineering shall notify the owner thereof that it constitutes a public nuisance and must be removed, and if the owner fails to do so, the Director of Engineering may abate the nuisance. Any and all actions undertaken by the Director of Engineering or his duly authorized agent to abate such a nuisance shall not attach any liability to the City, its agents, or employees. (RCW 47.36.180)
It's not a traffic offense, and no fine can be given by officers, it's not within their authority under this statute.