Manually update map with missing trip route

I am tracking a lifetime goal of hitting as many local hiking trails as I can however naturally some lifetime map is missing due to no phone reception. Is it possible to manually update this? The best solution would be to use something like OSM to manually record a GPS track and import that later which will then include speed and location. For super bonus points, a way to track and map vehicle data from a OBD harness would be fantastic (energy / regen etc).