OSM + Directions w/ Custom roads?

I am looking into using OSM w/ my own hosted tile server and adding custom roads/paths.

I am trying to figure out if any direction service (YOUR, MapQuest, OSRM, other?) will be able to go on these added custom roads?

So you want a basic routing database from original OSM data, and add some own ways to it?

I am not aware of such a feature of any OSM based routing engine, but I really recommend to contact the developer of each routing app … some projects have mailing lists or similar to ask.

I assume you are aware of the OSM wiki pages about Routing …

I don’t know of any public service that can add private roads for specific users. You’d better setup your own routing server using any existing opensource project (e.g. YOURS or OSRM). Then you can combine the OSM data with your private roads and use the combination for routing.

Maybe the best solution would be to add the private roads in OSM? Why don’t/can’t you?