I'm not sure how lawmakers would be supposed to make the law clear enough for people who think their own name is hearsay or redefine every single word in a sentence until the original meaning is mangled beyond recognition (Context and intention? What's that?).
Luckily, they don't have to.
As SpitfireIX mentioned, they only have to make them clear enough for the people whose job it actually is to interpret and enforce these laws.
He can, however, quote an outdated definition of the word "vehicle" from an outdated American Law dictionary which has no influence or bearing over Law whatsoever.
He can also quote an outdated definition of the word "driver" from an outdated American Law dictionary which has no influence or bearing over Law whatsoever.
It's worse than that. Quoting a definition, even an outdated one, would involve a modicum of honesty. Menard has to
lie about outdated definitions to make his point. He claims that "driver" is defined as "one who is engages in commerce on the highways". The
actual definition
was "one employed in conducting a coach, carriage, wagon, or other vehicle, with horses, mules, or other animals, or a bicycle, tricycle, or motor car, though not a street railroad car." It seems Rob doesn't understand that there is a difference between being employed to do something and being employed in doing something. His whole site is a monument to illiteracy.
The funniest part about Rob's shtick is that he essentially relies 100% on puns being a legal argument. In a country with two official languages, where both versions of a law have equal force as per its Constitution. So if a pun doesn't work in French, well, there goes that. All the retardedness regarding driving/driver, berths, benches, security, etc, are simply not present in French.