I think the owner/operator of routes is the primary source of the information. If a mapper finds that OSM differs from the situation on the road, (s)he can change it freely, as seen on the ground. The operator should monitor changes, there is tooling for that. I’m sure any differences can be easily resolved.
Tooling: Knooppuntnet Monitor can show the differences (on a map and with links editors) between the current route relation and a ‘frozen’ reference version of the same relation, for exactly this purpose: notice unscheduled changes and act on it.
1 Like