I think that regulations should set performance standards, rather than forbidding this or that. Does that answer your question?
In other words, you want a result. With the TGV lines, for instance, in France, I think it's 30 metres...and they can only emit 65 decibels. They're travelling at 300 kilometres an hour. That is their objective, and they meet it. If you set objectives for quality, you're going to get a lot further than if you legislate this activity or forbid that activity.