London Superloop

Background

A network of Green Line limited stop orbital routes was established by the London Transport Executive from 1953.^[3] Limited stop route X26 (now Superloop route SL7) from West Croydon to Heathrow Airport is a remnant of that network.^[4]

The 2008 mayoral election manifesto of Boris Johnson promised to trial orbital express bus routes in the outer suburbs.^[5] This led to an increase in frequency for the already existing X26 express bus route later that year.^[6] The policy had been abandoned by Johnson by March 2010, citing "plenty of good studies now which suggest to me that the big investment in orbital bus routes does not actually deliver the improvements that are sometimes claimed" and there was no further expansion of the orbital network.^[7][8]

Sadiq Khan became Mayor of London in 2016. In August 2017 the London Assembly Transport Committee called for more orbital and express bus routes in Outer London.^[9] The idea was included in the Mayor's Transport Strategy published in March 2018, with two new indicative express corridors in North London and one in South London:^[10]

• Heathrow Airport to Ilford via Harrow, Barnet and Enfield
• Chiswick to Ilford via Ealing, Wood Green and Walthamstow
• Bexleyheath to Beckenham via Bromley

In 2018 Transport for London began a policy of reducing bus services in inner London, where there had been a drop in passenger numbers, with plans to increase services in the outer suburbs.^[11] Limited-stop route X140 from Harrow to Heathrow Airport was introduced in December 2019.^[12] The new route was considered a success and expansion of the express bus network was included as a policy in the Bus action plan published by Transport for London in March 2022.^[13]

Phase 1

The Superloop branded proposal for a network of express orbital bus routes was announced on 28 March 2023 at a cost of £6 million.^[14][15] Transport for London noted that the proposals form part of improvements to transport in outer London in light of the expansion of the Ultra Low Emission Zone (ULEZ) in August 2023.^[16] The proposal was praised by the Campaign for Better Transport and Heathrow Airport Holdings,^[16] however Nick Rogers AM of the Conservative Party called the proposal a "superflop" drawing attention to the "repacking of existing [bus] routes".^[16] Caroline Pidgeon AM of the Liberal Democrats cautiously welcomed the proposals, following her previous campaigns for orbital bus services. Public consultations on the five entirely new routes that were announced took place between April and September 2023.^[17]

On 28 April 2023 further details of the proposals were announced and a consultation opened for route X183.^[18][19] On 9 June 2023 a consultation opened for route X34.^[20][21] On 14 July 2023 it was announced that route SL8, a renumbering of existing route 607, would be the first to operate as part of the Superloop service from the following day.^[22][23] The proposed route from Walthamstow to Royal Docks was revised to terminate at North Woolwich, and at the same time, the proposed route from Bexleyheath to Bromley was revised to terminate at Thamesmead.^[24]

On 7 September 2023 it was announced that routes SL1 and SL10 would be introduced in autumn 2023. Two stops in South Chingford and two stops in Meridian Water were added to the route of SL1 following feedback to the public consultation.^[25]

On 20 October 2023 it was announced that routes SL2 and SL3 would be introduced in spring 2024.^[26] On 5 December 2023 it was announced that route SL5 would be introduced on 3 February 2024.^[27] In March 2024, the loop was completed, with route SL4 to be introduced when the Silvertown Tunnel opens on 7 April 2025.^[28]

Phase 2

During the 2024 London mayoral election, Mayor of London Sadiq Khan proposed an additional 10 Superloop routes across London, as well as an express bus route via Old Kent Road prior to construction of the Bakerloo line extension taking place.^[15]

Proposals for routes BL1 (Waterloo to Lewisham, connecting with the Bakerloo line), SL11 (Abbey Wood to North Greenwich, connecting with the SL3) and SL12 (Rainham to Gants Hill, connecting with the SL2) were announced in January 2025.^[29]