Are you asking what is 'so complex' about public policy, safety, and economics? Even if this is only about maximum train length, which it isn't, the underlying

Are you asking what is 'so complex' about public policy, safety, and economics? Even if this is only about maximum train length, which it isn't, the underlying dynamics, as they are perceived by and affect all the stakeholders, are complex. This is what I mean by complex systems: https://en.m.wikipedia.org/wiki/Complex_system https://en.m.wikipedia.org/wiki/Complex_system Is this what you mean?