>>1240554Tramway third rails are only hot when there's a tram on top of them. So yeah, pretty safe.
Subways and heavy rail third rails are pretty much always powered, so don't touch those.
Bonus stage: any electrified system using the running rails for current return (so pretty much all of them but some weird ass 4-rails systems) can potentially fuck you up if something goes wrong with the earthing/feed back to the substation.