TfL confirms that Superloop SL15 is coming to Forest Hill in 2027

Transport for London (TfL) has confirmed that a new Superloop express bus route, the SL15, will launch in 2027, passing through Forest Hill as part of a cross-South London service linking Clapham Junction to Eltham.

The route will run from Clapham Junction through Clapham South, Tulse Hill, Forest Hill, Catford, Lewisham and on to Eltham, with a stop at West Dulwich on the return journey providing a direct link with Dulwich Village. The SL15 will connect with the London Overground Windrush line at Forest Hill, as well as National Rail and 77 other bus routes along the corridor.

The consultation, which ran from October to November 2025, attracted 1,897 responses. We're pleased to notice that Forest Hill (SE23) was the single most represented postcode, with 123 responses or 13% of all those who provided a postcode. This is a testament to how engaged our community is with local transport issues. 91% of respondents believed that the route would be more convenient for them, and 83% said it would cut journey times. The service will run every 12 minutes Monday to Saturday during the day, and every 15 minutes at other times including Sundays. Unfortunately, buses will be single-deck only, due to a low bridge at Thurlow Park Road near Tulse Hill.

Our submission to the consultation

The Forest Hill Society's Transport Committee responded to TfL's consultation last November. While we broadly welcomed the new route and its improved connections for Forest Hill residents, particularly towards the east, we felt the route as proposed was a missed opportunity.

Our key concern was that the South Circular has virtually no bus lanes along most of the proposed route, with only short stretches of bus priority between Forest Hill and Catford and on Battersea Rise. This means the SL15 will be caught in the same congestion that already affects the corridor, potentially undermining its reliability precisely when it is most needed. TfL acknowledged this but did not commit to new bus priority measures.

We also questioned whether Clapham Junction was the ideal western terminus. Forest Hill already has a direct rail connection to Clapham Junction both via the Windrush line on the Overground and the Victoria Loop trains, which also provide connections to intermediate destinations that the SL15 would bypass. We proposed instead that the route should terminate at Brixton, creating an east–west express linking Woolwich, Eltham, Catford, Forest Hill, Dulwich, Herne Hill and Brixton, serving areas that genuinely lack direct connections. An additional benefit of this alignment would be that the route could avoid the low bridge at Thurlow Park Road by turning off the South Circular at Croxted Road, enabling a double-decker fleet and significantly more capacity.

TfL's response was that extending to Woolwich would make the route too long to operate reliably, that Eltham–Woolwich connections already exist via routes 122 and 161, and that the western end of the SL15 fills a more unique gap. On double-deckers, they said they intend to use high-capacity single-deckers as mitigation.

Our proposals were not accepted in the final plan, but they are clearly on the record and the TfL consultation report summarises our submission in full. We will continue to make the case for bus priority measures along the route as planning progresses ahead of the 2027 launch.

What this means for Forest Hill

Despite our reservations, the SL15 is genuinely good news. A frequent express link westward to Clapham and eastward to Catford, Lewisham and Eltham will be a real improvement for residents who currently find east–west bus journeys slow and indirect. We will keep a close eye on developments and push TfL on reliability and capacity as the launch approaches.