The A21 Bromley Road and Bromley Hill, from Sangley Road in Catford to Avondale Road, will drop from 30mph to 20mph, with TfL's work due to start in early 2027.

The A21 Bromley Road south of Catford is going from 30mph to 20mph. Transport for London has put it in the next phase of its programme to lower speed limits on the roads it runs.

TfL lists the A21 Bromley Road and Bromley Hill, between Sangley Road and Avondale Road, under the London Borough of Lewisham. It says this phase “will commence in early 2027” (TfL Lowering Speed Limits Programme, read 30 October 2026).

Which stretch changes

Sangley Road meets Bromley Road at the southern edge of Catford. From there the A21 runs south through Bellingham and past Downham, then climbs Bromley Hill to Avondale Road, where the borough ends and Bromley begins.

So most of the new 20mph section is in Lewisham. It is the road’s whole run between Catford and the Bromley boundary.

TfL runs this road, not the council. The A21 is one of four TfL red routes through the borough, alongside the A2, the A20 and the A205 South Circular.

Phase 4 at a glance

Phase 4 covers seven places on TfL’s network. Four roads go from 30mph to 20mph:

  • A21 Bromley Road and Bromley Hill, Lewisham: Sangley Road to Avondale Road
  • A217 Swandon Way, Wandsworth
  • A24 Morden Road and Merantun Way, Merton
  • A232 Wickham Road, Croydon

The other three, in Hounslow, Barnet and Haringey, and Redbridge, go from 40mph to 30mph.

TfL gives no date more precise than early 2027. The work is new signs and new road markings. TfL says most of it will be done as “mobile works”, with little effect on traffic or people on foot. Road and pavement closures, with diversions, will be “a last resort”.

Why TfL is doing it

TfL’s Vision Zero Action Plan 2, published in March 2026, commits it to lowering the limit on at least a further 65km of its roads by 2030. That would make more than 80% of its roads in central and inner London 20mph.

The programme page gives the evidence TfL relies on:

Study Before After Change
Borough 20mph roads, 1989 to 2013: people killed or seriously injured 395 260 down 34%
Central London 20mph roads, May 2020 to June 2022: all collisions 405 304 down 25%
Same roads: collisions causing death or serious injury 94 71 down 24%

TfL compares the 34% fall on borough roads with a background fall of 15% over the same years. It also warns that the central London figures cover the pandemic, which may have affected the trend.

What it means for you

  • If you drive the A21 between Catford and Bromley: from some point in 2027, the limit will be 20mph all the way from Sangley Road to Avondale Road. Watch for new signs and markings once work starts.
  • If you live in Bellingham or Downham: expect short spells of mobile roadworks rather than long closures, if TfL works as its page describes.
  • If you want to comment: TfL’s page does not invite comments on phase 4. Each change needs a speed limit order, and TfL advertises one with a deadline for objections first. It has already done so for the Wandsworth road in the same phase (TfL notice, 23 October 2026). We will report the Bromley Road notice when it appears.

Live closures across the borough are on our Lewisham roadworks page.

Sources