The Jubilee line had originally been intended to go further east, but this plan had been abandoned. The revival of the extension plan was motivated by the urban renewal of the Docklands in east London and the overloading of the existing Docklands Light Railway. The extension was authorised in 1990 and finally opened in late 1999, in time for the North Greenwich tube station to serve the Millennium Dome.
The extension is marked by large platforms and halls that are only ever full in a busy rush hour. (North Greenwich in particular is far too large for the numbers using it, the Millennium Dome now being disused.) The most notable feature of the Extension is doors on the platforms that open when trains arrive, to stop people falling or jumping onto the track.