Unless there are extenuating circumstances, any reasonable traveler will transfer from the top line to the bottom line at the leftmost stop. But that's not what we find. In fact, we find transferring at the rightmost stop, because the second route hits that stop first and we greedily board.
This will solve a ladder transfer issue. Consider the following two lines on the same street in opposite directions
Unless there are extenuating circumstances, any reasonable traveler will transfer from the top line to the bottom line at the leftmost stop. But that's not what we find. In fact, we find transferring at the rightmost stop, because the second route hits that stop first and we greedily board.