valhalla
Match OSM Way ID offsets to edges
Some providers of live traffic services offer an OSM Way IDs as an alternative referencing method next to Openlr. They usually use meter offsets from the start/end of the way to specify the exact segment. Since Valhalla typically chops up ways, a mapping is needed where edges that make up a way in OSM are ordered topologically and are annotated with their length. valhalla_ways_to_edges doesn't order edges in any meaningful way nor does it spit out their length.
One option to solve this would be to patch the ways_to_edges script, but without more information, we won't be able to properly sort edges that are part of loops (e.g. roundabouts). So I think the only solution is to create this mapping optionally during the graph build, where we can carry information on where a way starts and where it ends, so that we don't have to store it in edgeinfo where it will only ever be needed once :smile:
