Of course there is no such technical _need_, most kinds of these needs are drive...

nattofriends on May 11, 2016 | parent | context | favorite | on: Exploring the Elizabeth line, one of the world’s l...

Of course there is no such technical _need_, most kinds of these needs are driven by _legal_ requirements founded in fear of full automation. Fully automated systems were realized before your example already in Vancouver's SkyTrain (1986) and even BART was supposed to be specified to be fully automatic.