Is London’s SL15 route about to transform commuting between Bromley and Croydon?

Transport for London (TfL) has unveiled detailed plans for a brand-new express bus service — the SL15 Superloop — connecting Eltham to Clapham Junction in what officials describe as a major step toward improving cross-London mobility.

The long-anticipated route aims to tackle one of South London’s most persistent problems: the lack of efficient bus connections between key neighborhoods. The SL15 will run as a limited-stop service, linking major transport hubs including Eltham Station, Catford, Forest Hill, West Dulwich, Tulse Hill, Streatham Place, Clapham South, and finally, Clapham Junction.

Unlike traditional bus routes that make frequent stops, the SL15 is designed to offer faster travel times and direct connections between areas that have long been isolated by poor transport links. In Eltham, the bus will stop only at the western end of the High Street, with additional stops at Yorkshire Grey Roundabout, Baring Road, Lewisham Town Hall, and Catford Bridge Station. From there, it will continue toward Forest Hill, Wood Vale, and West Dulwich before completing its journey through Streatham and Clapham.

A New Era of Connectivity

According to TfL, the route’s main goal is to enhance connectivity across South London by linking multiple rail and underground services. Passengers will be able to interchange with Southeastern services at Eltham, Thameslink at Catford, London Overground and Southern Rail at Forest Hill, Northern Line at Clapham South, and South Western Railway at Clapham Junction.

This expansion forms part of the Superloop initiative, a network of orbital express bus routes around London, first announced by Mayor Sadiq Khan. The SL15 is one of the flagship additions under the second phase of this program, following the recent launch of the BL1 from Lewisham to Waterloo.

Design and Service Frequency

Due to a low railway bridge near Tulse Hill, the SL15 will exclusively use single-decker buses. However, the frequency remains consistent with other Superloop services — every 12 minutes during daytime hours from Monday to Saturday, and every 15 minutes during evenings and Sundays.

TfL projects that the full Eltham-to-Clapham journey could take up to 70 minutes, depending on traffic conditions along busy corridors like Brownhill Road and Dulwich Common. Nevertheless, the express service is expected to be a cost-effective alternative to train routes that require traveling through Central London.

Balancing Expansion and Reductions

While the SL15 is being celebrated as an addition, concerns remain over service cuts elsewhere. TfL has already confirmed the removal of the 472 bus route, which will be replaced by the SL11 between North Greenwich and Abbey Wood in early 2026. Critics argue that the move will negatively affect new housing developments in Thamesmead, Plumstead, Woolwich, and Charlton, where residents rely on the 472 for daily commutes.

In contrast, the SL15 will complement existing services such as the P13, 160, and 185, providing an extra layer of mobility for South London commuters.

The SL15’s introduction is slated for mid-2026, following the completion of ongoing consultations. TfL maintains that the route represents progress toward its goal of creating a more connected, sustainable, and accessible London transport network.

For residents of Eltham and beyond, the SL15 could finally bridge long-standing transport gaps — provided it can overcome South London’s infamous traffic bottlenecks.

FAQ Section

TfL expects the SL15 to begin service around mid-2026 after consultation and final approval.

The express route will connect Eltham to Clapham Junction via Catford, Forest Hill, West Dulwich, Tulse Hill, Streatham, and Clapham South.

Every 12 minutes during weekdays and Saturdays, and every 15 minutes during evenings and Sundays.

A low bridge at Tulse Hill prevents double-decker buses from safely passing through the route.

No. Unlike the SL11, which will replace the 472, the SL15 is an entirely new addition to the network.