Sutton Link

From the Wikipedia page

The Sutton Link is a planned new Tramlink line or separate bus rapid transit (BRT) in London, between Wimbledon/or Colliers Wood via St Helier to Sutton. It may be owned by London Trams or a separate body, which would be an arm of Transport for London (TfL).

The previous Mayor of London Boris Johnson said in July 2013, that their was a reasonable business case for Tramlink to cover corridor between Wimbledon and Sutton and a map explaining the planned routing and stops followed. It would leave the existing route just to the east of Morden Road and head along the A24 and A297 to Rosehill Roundabout, then the B2230 through Sutton town centre, ending at the station and include a loop via the St Helier Hospital and a possible extension to Royal Marsden Hospital also are shown.

More information here.