I go through the tunnel on my morning runs and once tried to map the length of my route using the walking option on Google Maps. However, I found the tunnel and the footpath through it were missing from their map. So I emailed Google the tunnel location and what the footpath through it connected. Three weeks later, I got an email that they verified the tunnel and path existence and location, and they now appear on Google Maps. So now the tunnel is officially a part of the 21st century!