But it is what it says. That's likely the intent, much as thermionic says, but not the literal phrasing of the law. It literally says "on level ground".

On a downhill grade, it does not have a 20mph cuttoff, ostensibly because a bike could simply coast at greater speeds - it has everything to do with grade. But it also does not exclude uphill, which is a flaw in the law as written.

So the question is, how far can you take a literal reading of the law? Courts only interpret intent when the literal reading of the law is ambiguous, as the literal law is presumed to be the intent regardless of how much sense it makes - it seems pretty clearly written in this case, not ambiguous.

Any lawyers to chime in here?