Before revision:  As in Cabello's work, our algorithm can also compute the Wiener index of ( sum of all pairwise distances in) a planar graph, within the same bounds  .
After revision:  As in Cabello's work, our algorithm can also compute the Wiener index of ( sum of all pairwise distances in) a planar graph, within the same bounds Cohen-Addad et al., FOCS'17 .