Neat project! It really gives you a good idea of how the FAA has designed SIDs and STARs to consolidate traffic into "lanes."
LAX You can clearly see where they want all their traffic to go (and is a fairly simple, easy setup, and what looks like a few sidesteps). While at JFK You can see how they must deal with aircraft landing and departing in all directions, and the use of runways designated for specific directions, as well as the split depending on the direction of flight and assigned "climb."
Simple, effective visualization.