Ever flown IFR in a non-radar environment? Most pilots haven't, because the MEAs are above the minimum radar coverage altitude across most of the United States. But that's definitely not the case for aircraft crossing from Europe to North America in the North Atlantic Organized Track System. It seems archaic, but this is how modern jetliners avoid hitting each other flying back and forth from London to New York. I found this gave me a better appreciation for why the instrument flight rules are structured the way they are. The system really does need to be able to accommodate aircraft in a non-radar environment, with terrible communications capability, with no ground based NAVAIDs.