Comment by tazjin

Of course they do in Moscow too, the metropolitan/commuter areas exist in most big cities. Seems to be about 8 million less than Moscow for Paris, 6 million less for London, based on what Wikipedia currently says about the respective metropolitan areas.

For what it's worth, I lived in London for some time and its commuter rail system is much less integrated and much more confusing (with different companies, incompatible tickets and so on). In the city it's fine, though the tube isn't very comfortable (except for, ironically, its oldest lines which have luxuries such as ventilation).