Key Points
- Transport for London (TfL) plans to introduce a new express bus route named SL15, part of the Superloop network.
- The SL15 will run between Eltham and Clapham Junction via busy south London locations such as Catford, Forest Hill, West Dulwich, and Clapham South.
- The route will primarily follow the South Circular Road and offer limited stops to ensure faster journeys.
- There will be eight major interchanges including Thameslink at Catford, Northern Line at Clapham South, and London Overground at Forest Hill.
- Due to a low bridge near Tulse Hill, only single-decker buses can be used on the SL15 route.
- The service aims to address the poor connection between South London areas and will provide an option cheaper and more convenient than existing routes, although end-to-end journeys may take up to 70 minutes due to traffic.
- The SL15 will operate every 12 minutes Monday to Saturday, and every 15 minutes during Sunday and evenings.
- This new route is part of the expanding Superloop express bus network, which already covers several parts of London, including the recent Bakerloop (BL1) route connecting Waterloo and Lewisham.
- The Bakerloop offers frequent electric bus services and is free for the first week of operation, highlighting TfL’s commitment to improving south London transport.
- Mayor of London Sadiq Khan supports enhancing transport links with express routes like the Superloop ahead of long-term projects like the Bakerloo line extension.
What is the new express bus service planned for South London?
As reported by Secret LDN on 21 October 2025, Transport for London has revealed plans for a new speedy bus route called the SL15, set to connect Eltham in the east with Clapham Junction in the west of South London. This new service will be part of the Superloop family, a network of express bus routes designed to speed up orbital travel around London, bypassing the need to travel into the central city to change lines. The SL15 will run largely along the South Circular Road, linking key transport hubs and busy South London suburbs such as Catford, Forest Hill, West Dulwich, Tulse Hill, Streatham, and Clapham South.
How will the SL15 Superloop route improve connectivity in South London?
The SL15 is designed to help address South London’s reputation for being poorly connected by public transport despite its population and urban spread. The express service will have fewer stops compared to regular buses, aimed at reducing travel times across the route. It will offer eight inter-rail change options, including significant connections like Thameslink at Catford, the Northern Line at Clapham South, and the London Overground at Forest Hill station. This ensures passengers can easily transfer to faster rail services as part of their journey.
An important detail highlighted by TfL is that due to a low railway bridge near Tulse Hill, only single-decker buses will be able to run the route, which is a technical limitation impacting vehicle choice. The full journey time can take up to 70 minutes in traffic, but it is still considered a more economical and convenient option than travelling into central London and back out again.
What are the operational details of the SL15 service?
According to TfL’s public consultation update on 19 October 2025, the SL15 will provide frequent service with buses running every 12 minutes during Mondays to Saturdays in the daytime. Services will reduce slightly in frequency to every 15 minutes on Sundays and during weekday early mornings and evenings. The route stops include less congested areas in Eltham town centre and major transport interchanges to maximise connectivity.
How does the SL15 fit into the larger Superloop bus network?
The Superloop is an orbital network of express bus routes intended to provide fast, efficient connections across outer London boroughs. The first phase, which launched in July 2023, completed a network of 10 routes circulating the city’s outskirts. TfL has continually expanded this network, including new routes such as the Bakerloop (BL1), which launched in late September 2025 and links Waterloo to Lewisham with frequent electric double-decker buses.
The Bakerloop has been particularly well-received, offering free rides in its first week and running frequent services aimed at providing faster, greener, and more direct journeys. Brenda Dacres, Mayor of Lewisham, expressed strong support for these new services while also emphasising the continued importance of the Bakerloo line extension as a complementary longer-term infrastructure solution for South London.
What are officials saying about these new bus routes?
Mayor of London Sadiq Khan has publicly endorsed both the Superloop expansions and the Bakerloop service. He emphasised the immediate benefits of the new express bus services in improving connectivity while longer-term projects like the Bakerloo line extension continue in planning. Khan stated,
“Constructing a Bakerloo line extension will take a significant amount of time, and I do not wish to delay any longer in enhancing transport links for the residents of London.”
The Bakerloop launch is part of this vision to provide faster, environmentally friendly transport options immediately.
Brenda Dacres underscored that while the new buses are a positive development for South London’s transport, there remain gaps in service and that rail extensions remain vital for fully meeting the capital’s transport needs.
What challenges does the SL15 face, and what is its potential impact?
Challenges for the SL15 route include navigating some of South London’s traffic hotspots such as Brownhill Road and Dulwich Common, which may slow buses and increase journey times. However, by offering an express bus that efficiently links key hubs, the service aims to provide a useful alternative to current bus and rail journeys, which often involve detours into Central London. Its integration with multiple rail lines will enhance multimodal travel options and potentially reduce congestion on other routes.
Overall, the SL15 is part of a larger vision by TfL to improve orbital travel and create more frequent, reliable, and accessible public transport services outside London’s centre, supporting economic growth and better quality of life for outer London communities.
London’s new SL15 express bus route as part of the Superloop network represents a significant investment in improving South London’s transport connectivity. By linking Eltham and Clapham Junction with fast, limited-stop service and numerous rail connections, TfL aims to address longstanding transport gaps and provide residents with quicker, more convenient travel options. Support from figures like Mayor Sadiq Khan and Lewisham Mayor Brenda Dacres highlights the critical role these routes play alongside ongoing major projects like the Bakerloo line extension. While some operational challenges remain, the service promises to be a valuable addition to South London’s transport landscape.
