To extend the comment about Strava - look into http://wandrer.earth/
It will take your strava activities and map them together, showing what roads/paths you've run and those you haven't.
The free level gives you the last 50 activities, or join and it will load all your strava activities, over 8,000 for me (took a couple of days to fully import)
As a cyclist with a 1 hour commute each way, I have many routes to choose from. It is amazing how many roads I go past and have never ever been down in a decade of Strava usage.
Example1: Here's a map showing the roads I've never been down in Red. I might plan a route that ticks off those few roads, and raises my % complete
above 70.74% as pictured.
People being people like to work toward "completion", and having 90, 99, or 100% completeness for a suburb is an attainable goal.
Example2: this map shows the gap where bike breakdowns made me walk to the nearest end, be it work or home: