...On what planet does someone need a law to tell them not to ride on the tracks?
This one: it's Darwin's Law
And exactly which bicycle produced to date would actually "get in the way" of a train?
Any bicycle produced to date would cause a train to stop - after it thoroughly mangled the bicycle and rider. What a bother...
There is a difference between regulation (we all drive on the right side of the road, maintain speed limits, etc) and revenue generation. I'm perfectly fine with the former as it standardizes the expectations for sharing publicly owned roads. I'm even okay with citations for violations of those regulations. But requiring licensing, plating, registration is nothing more than a means to pad the coffers of the state. There are no legitimate reasons to require licensing and registration of vehicles except to steal more money from the people.