Hey OSM-SAMOA,
Thanks for your great work and collaborative replies. I am looking forward to seeing the OSM data in Samoa improve. After performing a JOSM validation of Upolu, I identified some validation flags that I later fixed; there were a few more instances of highway duplicate nodes (https://www.openstreetmap.org/changeset/167401168), overlapping highways (https://www.openstreetmap.org/changeset/167402591), and crossing highways (https://www.openstreetmap.org/changeset/167404644). Please let me know if you need any additional help with your project.
-ChromeLotus