I suspect the mayor's goal was to eliminate driver confusion, not to prevent this article from being written.
Why the downvoting? I was just pointing that the OC makes a non argument. If one wants to prevent ambiguity of the text, and one thinks that the evenness of is not clear for the intended audience, one adds a appositive parenthesis reinforcing that fact.
It looks like you meant "'an even number, which includes zero' for that effect", but on first reading, it appeared to me (and perhaps your downvoters), that you meant "'an even number', which includes zero for that effect", which would be a significantly less productive comment.