I do “digital quality” projects for the national operator (Wandelnet). I compare their routes (gpx-s) to the route in OSM, which gives a list of differnces. Then I ask the field operatives who is right, OSM or their website. If theirs is right, I adjust OSM and ditch the issue. If OSM is right, I keep the issue. If none is right, I ask for the correct route, then adjust OSM, and keep the issue.
In the end, there is a list of issues that should be corrected on the operator’s website. They usually correct the whole thing within a few days. We are talking about routes between 100 Km and 400 Km.
The Belgian community does comparable projects with their national operator. They even have created a tool: Knooppuntnet Monitor. This tool checks the relation for breaks, and does the comparison between a gpx and the OSM route. It’s still in development, but I have used it succesfully for one regional route (200 Km). The nice thing is, the differences requiring OSM adjustment, automatically disappear from the list.
And, the operator can get access to see what needs to be done, and can load a new gpx when it’s done. You could even give the field operatives access so they can monitor and adjust their own section of the trail.
I know the French had a tool to support relation maintenance, not sure if it still works. They had a Telegram group for that.
Biggest problem of both: they don’t support hierarchical relations. Which is really necessary for iwn routes. I know Knooppuntnet Monitor will solve this issue, just not sure when!
I would sure like to know if there are other tools like this to support route mapping and maintenance!
PS. The national operator gets the correct routes from me in the form of gpx’s, one per daily stage, as sectioned on their website. Since they discovered how accurate the OSM-routes are, they simply copy our route to their GIS.
At first they couldn’t believe how accurate OSM is, because they were used to lines drawn loosely on a picture, and now they get a line following exactly the paths and roads where the waymarked trail is.
I explained to them that a route in OSM is the exact string of ways you walk when you follow the signage.