Tesla superchargers lend themselves well to this problem because of the way the sites were selected. Tesla obviously wants these sites to form clear routes, and

Tesla superchargers lend themselves well to this problem because of the way the sites were selected. Tesla obviously wants these sites to form clear routes, and they advertise when they hit certain milestones ("NY to San Francisco all on the supercharger network!"). Which explains why the optimal route looks so nice. Very interesting read, well done.