Just gotta be aware of people around you. If I am lapping and decide to do in between rail lines I always check up to make sure there isn't a rider skiing the continuous line, and if there is I always yield. Whoever had the analogy for merging onto the highway is completely how I ride the park.
And at the standard drop points for lines I usually just play it like a 4 way stop sign intersection in order to decide who drops next.