Hello Mappers
                   I caused a few routing errors when I first started mapping because I didn't check that the final node of a path I had mapped was connected to another path, track or road. I didn't know about routing then. Seeing an image of a dotted path at a road looked to be an obvious connection. But when using a routing engine routing would fail.
     Since I started to use routing engines more. I have discovered more faults. They are often caused by tagging omissions.  Unless a way allows the mode of transport that you have selected the routing engines will not use that  way ( path track or road).   Some mappers in England know that a Bridleway is a legal right of way for foot, cycles and horses and  they assume routers will use these ways, But they don't.  For any rights of way we need to add https://wiki.openstreetmap.org/wiki/Tag:foot=yes for footpaths.  Bridleways  need all three tags,  foot =yes, https://wiki.openstreetmap.org/wiki/Tag:cycle=yes, and https://wiki.openstreetmap.org/wiki/Tag:horse=yes, to get routing engines to work as expected.   Potlatch and iD editors have these  tags built-in but you will have to select  each one of them.   When we edit the map the database is changed instantly,  the drawn map will maybe need a refresh to renew the display however. (ctrl  F5  on my Win PC)   We would hope we could quickly test the routing after our mapping or correction, but we cannot. OSRM and GraphHopper only update their copy of the map data every few days.  For this reason we will have to check a few days later.  see this please https://help.openstreetmap.org/questions/83945/foot-routing-failing-bridleway-alone-doesnt-let-it-work-it-needs-footyes
                                                                                                                                              Happy Mapping and Routing
                                             Andy