Numerous extensions to the network have been discussed or proposed over the years, involving varying degrees of support and investigative effort. During 2002, as part of The Mayor's Transport Strategy for London, a number of proposed extensions were identified, including to Sutton from Wimbledon or Mitcham; to Crystal Palace; to Colliers Wood/Tooting; and along the A23. The Strategy said that "extensions to the network could, in principle, be developed at relatively modest cost where there is potential demand..." and sought initial views on the viability of a number of extensions by summer 2002. In 2006, in a TfL consultation on an extension to Crystal Palace, three options were presented: on-street, off-street and a mixture of the two. After the consultation, the off-street option was favoured, to include
Crystal Palace Station and Crystal Palace Parade. TfL stated in 2008 that due to lack of funding the plans for this extension would not be taken forward. They were revived shortly after Boris Johnson's re-election as Mayor in May 2012, but six months later they were cancelled again. During November 2014, a 15-year plan, Trams 2030, called for upgrades to increase capacity on the network in line with an expected increase in ridership to 60million passengers by 2031 (although the passenger numbers at the time (2013/14: 31.2 million) have not been exceeded since (as at 2019)). The upgrades were to improve reliability, support regeneration in the Croydon metropolitan centre, and future-proof the network for
Crossrail 2, a potential
Bakerloo line extension, and extensions to the tram network itself to a wide variety of destinations. The plans involve dual-tracking across the network and introducing diverting loops on either side of Croydon, allowing for a higher frequency of trams on all four branches without increasing congestion in central Croydon. The £737million investment was to be funded by the Croydon Growth Zone, TfL Business Plan, housing levies, and the respective boroughs, and by the affected developers. All the various developments, if implemented, could theoretically require an increase in the fleet from 30 to up to 80 trams (depending on whether longer trams or coupled trams are used). As such, an increase in depot and stabling capacity would also be required; enlargement of the current Therapia Lane site, as well as sites near the Elmers End and Harrington Road tram stops, were shortlisted. In 2014, a proposed £320M scheme for a new line to connect Wimbledon to Sutton via Morden was made and brought to consultation jointly by the London Boroughs of Merton and Sutton. Although £100M from TfL was initially secured in the draft 2016/17 budget, this was subsequently reallocated. In 2018, TfL opened a consultation on proposals for a connection to Sutton, with three route options: from
South Wimbledon, from
Colliers Wood (both having an option of a
bus rapid transit route or a tram line) or from
Wimbledon (only as a tram line). During February 2020, following the consultation, TfL announced their preference for a north–south tramway between Colliers Wood and Sutton town centre, with a projected cost of £425M, on the condition of securing additional funding. Work on the project stopped in July 2020, as Transport for London could not find sufficient funding for it to continue. expressing their support for "Route Option 2 (Colliers Wood – Sutton) operated as a tram service ... assuming we are successful in securing funding to deliver the project"., On 24 July 2020, the project was temporarily put on hold due to the
COVID-19 pandemic. TfL said they were pausing development work on the scheme "as the transport case is poor and there remains a significant funding gap".
Andy Byford,
London's Transport Commissioner, said that this involves making 'difficult choices' about which projects can be funded. During 2023,
Sutton's council leader Ruth Dombey advocated for the project and urged TfL and the
mayor's office to provide fair and adequate funding, especially in light of the
ULEZ charge. However, London Mayor
Sadiq Khan dismissed the project as inadequate and pointed out the £440M funding shortfall. London Mayor Sadiq Khan faced criticism from Sutton MP
Paul Scully on 21 April 2023, for the delayed Sutton tram extension project and implementing the
Ultra Low Emission Zone charge without sufficient public transport alternatives, while defending the delay citing a £440M funding gap. In December 2023, TfL stated that further progress will depend on funding agreements with other stakeholders such as local councils, the
Department for Transport, as well as
Government, and that the Sutton Link is currently the only extension being considered. Rival proposals included new bus routes. ==Accidents and incidents==