There's no subway line in Toronto to the airport as well. Presumably people change from the Metro to the RER all the time. Unlike GO, the RER service operates at subway-like intervals, and is part of the same fare-system. They are effectively the same system.No subway line direct to the airport in Paris There's the RER, which sees lots of people ride with luggage, but those are larger trains with more space. I've been part of a group of 6 fresh off the plane with luggage in tow to get on the RER to Gare du Nord and then transfer to the Metro. No one seemed to mind, but it could be due to the sardine conditions that always exist on the Paris Metro.