I can’t recall ever hearing it tried. While traffic tickets constitute a great deal of most of the populace’ interaction with the justice system and thusly generate defense schemes way out of proportion to their gravity, few such schemes are, I think, pursued, once cost is weighed in.
Who knows what unintended effects might bubble up out of your proposed argument?
As long as we’re on the subject of traffic violation defense, let me ask those who might be knowledgeable. I lived in Japan in the 1950’s (I was a kid then), and it was “common knowledge” in the expat community that a reliable defense in a traffic accident case was the presentation of evidence to the effect that one was intoxicated. Sounds too good to be true, but that is what my Daddy told me. Anybody got the straight dope on that?
If you plead insanity, it means you admit you are unstable. Most state would yank your drivers license if you were deemed to be mentally ill. You would also lose other rights and privilages, such as gun ownership, if you are found to be crazy. Not worth it just to get out of a traffic fine!
Best advice is, buy a Valentine One, drive with your brights on, and if you get nailed anyway, plead not guilty & hope the cop doesn’t show up to testify. (His day off, vacation, etc.)
You’d get into more trouble by admitting you know that you are mentally unstable, not only would they yank you license they could arrest you right there for reckless driving. Well, maybe. Or if you lived in a sitcom the judge would look at you and say, “You so crazy!” and the credits would roll.