Vancouver SkyTrain opened in 1985 and was fully automated from day one. The rolling stock used on the majority of the system (Bombardier ART) was specifically designed for driverless operation.
Interestingly, at the time the Vancouver SkyTrain was undergoing construction, the same tech was being installed in Toronto for the Scarborough rapid transit line. The transit union in Toronto opposed automation, so the trains had to be specially modified to add operator cabins so the trains could be driven manually. Vancouver was able to get away with it because the system was a greenfield project, there was no union of subway workers around already to oppose automating the trains.
Interestingly, at the time the Vancouver SkyTrain was undergoing construction, the same tech was being installed in Toronto for the Scarborough rapid transit line. The transit union in Toronto opposed automation, so the trains had to be specially modified to add operator cabins so the trains could be driven manually. Vancouver was able to get away with it because the system was a greenfield project, there was no union of subway workers around already to oppose automating the trains.