[rhino369]

>Many legal things are evaluated lazily: the law may not specify exactly what the vehicle is, but if such need arises, there are tools, like precedents and analogy, to answer this question.

That's how common law and precedents work in the US system. Case A from 1924 said cars were vehicles, but bikes weren't. Case B from 1965 said e-bikes weren't vehicles. Case C said motorcycles were vehicles. And then the judge analogizes the facts and find that an electric motorcycle is a vehicle so long as its not a e-bike.

But the administrative law side of things works the opposite. They publish a regulation just saying "e-bikes above a certain weight qualify as vehicles under Law X."