There was an automatic light rail to Docklands in London when I last visited. In 1991.
Helsinki metro was planning to have automated trains when the western extension opens in 2014. It opened in late 2017, without automation because of technical difficulties. I have a hard time believing there will be much automated traffic on the roads here (with uneven surfaces, unclear markings, snow, and other traffic) before the metro can be automated (in a dedicated tunnel where there is no other traffic, movement is technically only possible on the rails and there is no snow).
Docklands opened in 1987 but is only GOA3 (the train runs automatically but requires a staff member responsible for departure & emergency situations).
Port Island Line (Kobe) opened as GOA4 (fully automated) in 1981 followed by Lille Metro in 1983 and Vancouver's SkyTrain in 1985.
The US has several GOA4 systems, though they're mostly airport shuttles and people movers (AeroTrain at Dulles, Monorail at Tampa, STS at Tacoma) a few serve actual communities (DPM, Metromover, Morgantown, Las Vegas Monorail).
> Helsinki metro was planning to have automated trains when the western extension opens in 2014. It opened in late 2017, without automation because of technical difficulties.
The main cause of the cancellation was political: there were difficulties with the supplier (Siemens) and the price spiralled up to the point where it would never have paid off.
The Helsinki Metro is also a bit unusual in that it uses Russian wide gauge track (for compatability with the rest of the rail system) but Western tech otherwise, meaning basically everything has to be custom made and is priced accordingly.
I don't really think the rail gauge causes any difficulties for automating the system, though. Tram gauges vary a lot and what manufacturers do is just use the same design and put underneath a different width bogie (wheelset).
(The Finnish rail gauge is in fact nominally different from the current one in Russia, because USSR changed from "imperialist" 1524 mm to "metric" 1520 mm between 1970 and 1990; the trains are in practice compatible, though.)
And here we are approaching the crux of the issue. Building a new line so it's fully automatic is relatively straightforward. Re-engineering an existing line to make it automatic (without shutting it down for months, which understandably is rarely an option) is like performing open heart surgery on a patient while he is running a marathon.
Well, and the SSR is particularly hard (given National Rail services run on parts of the LU-owned SSR infrastructure); the Northern Line automation was nowhere near as painful.
Helsinki metro was planning to have automated trains when the western extension opens in 2014. It opened in late 2017, without automation because of technical difficulties. I have a hard time believing there will be much automated traffic on the roads here (with uneven surfaces, unclear markings, snow, and other traffic) before the metro can be automated (in a dedicated tunnel where there is no other traffic, movement is technically only possible on the rails and there is no snow).