Random free idea: Grab image frames from the drivers' Phone camera and use that to figure out if the road exists where OSM doesn't have one. Supplement your own Kalman Filter and update your maps!
The issue isn't about missing roads. Most problematic are missing places when searching by business name or wrong/missing address numbers. (I work in the industry) Pelias project helps a lot, but there's still more data + software work to be done.
This is quite the understatement. I used to work for a company selling a personal safety device that paired with your phone and the data we would get back for location on some Android phones was just atrocious. On a large number of older Pixel devices, we’d routinely see location off by a large margin (as in over a mile in the worst cases). Interestingly, we’d see the “real” user location provided with a location accuracy of 100-400ft, then the device would radically jump to a new location (again, sometimes over a mile away) with a location accuracy of <50ft. When you are dispatching help to a person in an emergency, exact location matters!