Thanks! I'll look at the PR soon. But just FYI, I don't plan on doing any more work on this repo, because there's no need for it. The approach I started in https://github.com/dabreegster/routing-engines where summing counts by (OSM node1, node2) pairs and looking up geometry and edge attributes later is going to be much more performant, simpler, and avoid hairy issues with bridge/tunnel crossings. I'll try and write up that approach in more detail and send it around tomorrow

Sounds good Dustin, I think your approach with using the nodes directly sounds really good. 👍 to performance, simplicity and avoiding hairy issues (from which the R implementation of overline() may suffer from as it has few tests).