Google Maps is one software that has impressed me a lot. I used to wonder how it works. I still don't understand it's precise functioning however I can tell you my point of view.
Android mobile is a very helpful gadget to Google than it's to you. As you must be already knowing that android keeps track of your location history. That history is uploaded to the Google servers that is employed by Google to convey you directions and different services
Say as an example a thousand individuals with android devices used to take a path daily. but all of a sudden it went all the way down to ZERO. now Google's algorithm will track that change and advise you not to take that path and will recommend you a another path.
This is how Google is ready to provide you close to real time traffic updates. therefore if you travel through a path, Google will use your information i.e the distance, path, time etc to tell close to real time traffic on that path to others.
It also collect information from your device solely using Location history settings. As this can be by-default on, one at first don't search for it and disable it. So, Google get all location visiting by you whenever your device location is on.
Google saved your location history together with your Logged In google Account. to get your location history in your smartphone, just open Google Map → Settings → under Personal Content → Location settings.
Here you'll be able to view whether or not location history is **ON or OFF in your device. and conjointly checked your all location on Map Timeline,** Year, Month & Date
On Desktop In your Google Account, Visit to Activity control Section → Location section, Here you'll be able to **manage Activity
Google also partner with “the most comprehensive and authoritative data sources” via its Base Map Partner Program. a huge number of agencies submit elaborate vector data to Google, and these agencies include the USDA Forest Service, the US national park Service, the US geological Survey, various city and country, and so on.MORE HERE