Google Maps data source: user Navigation usage?

With the latest update of Google Maps in my area (in Italy), I noticed that the map now shows a small road that goes around the apartment block where I live, this road is closed by a private gate accessible only for residents. It is not even an official road, just a service road for the block.

My question is why did Google add this road to the maps, when in the same area there are other service road in the same situation which are not on the map?

One possibility is that the source is ME, I constantly use my Android with Google maps, Navigator and Waze when I go driving around.

is this possible? does Google use the data collected by the use of Maps/Navigator over time to plot new roads ??

Also to confirm my theory is that the signature in the lower corner of the map says "Map data ©2012 Google", so it is not some private company that provided the maps, but Google themselves.