This map seen at Reddit is informative. It shows all the streets covered by GoogleStreets, condensed onto a world map. In most of the world the streets are where the people are. Northern Canada, northern Russia, inner Australia, and the Amazon region are blank because no cities or roads are there.
Some entire countries are missing. All of the Islamic world is blank. China and Belarus are blank. Most of Africa, except the former British colonies, is blank.
Incidentally, one of those old Chevy promotional films illustrates how maps were updated through most of the 20th century. The AAA maintained a crew of Road Scouts who constantly drove all the roads, charting every detour or construction zone or change of population since their last visit. In the film they were driving Chevies, of course. The road scouts called in their data regularly, and mapmakers used layers of transparency to update the details. Google’s Road Scouts still drive everywhere in cars; only their data system is new.
Polistra's Mill 
