TfL will cut the A21 from 30mph to 20mph from Catford to Avondale Road, at the Bromley boundary, with the work due to start in early 2027. Buses are unchanged.

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

TfL’s programme page lists the A21 Bromley Road and Bromley Hill, between Sangley Road and Avondale Road, as one of seven locations in phase 4. It says phase 4 “will commence in early 2027”. Source: TfL Lowering Speed Limits Programme, read on 30 October 2026.

Where the new limit runs

Sangley Road is in Catford. Avondale Road meets the A21 at the boundary between Lewisham and Bromley, about a mile north of Bromley town centre. That is roughly two miles of road. TfL files the scheme under the London Borough of Lewisham, because nearly all of it is on the Lewisham side.

So the 20mph section will cover the whole run through Downham and up Bromley Hill, and end where the road enters the borough. It is the main road route between Bromley town centre and Catford and Lewisham.

TfL, not the council, is in charge of it. Bromley Council’s own page says the A21 is a TfL red route from the M25 to the Lewisham boundary at Bromley Hill (Bromley Council red routes).

The other roads in phase 4

TfL lists four roads going from 30mph to 20mph:

  • A21 Bromley Road and Bromley Hill, Lewisham: Sangley Road to Avondale Road
  • A217 Swandon Way, Wandsworth: Wandsworth Roundabout to Fairfield Street
  • A24 Morden Road and Merantun Way, Merton
  • A232 Wickham Road, Croydon: Shirley Road to Monks Orchard Road

The A232 stretch is in Shirley, in Croydon, on the road between Croydon and West Wickham. Three more roads, in Hounslow, Barnet and Haringey, and Redbridge, drop from 40mph to 30mph.

How the change will be made

TfL says the work is new signs and new road markings. Most of it will be done as “mobile works”, with little effect on traffic or pedestrians. It says road and pavement closures, with diversions, will be used only “as a last resort”.

The page gives no date more precise than early 2027.

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. It wants 20mph as the default in central and inner London, and a 40mph maximum where people live or catch buses.

The programme page sets out the evidence TfL relies on:

Study Before After Change
150-plus borough 20mph schemes, 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%

The background fall across London over the borough study period was 15%. TfL itself warns that the central London figures cover the pandemic, so the trend “should be interpreted with caution”.

What it means for you

  • If you drive the A21 to Catford or Lewisham, expect a 20mph limit from the borough boundary at Avondale Road all the way to Sangley Road once the new signs go up in 2027. At the moment it is 30mph.
  • If you catch the bus, nothing changes to the routes. TfL’s page for its Bromley Road bus lane lists the 47, 54, 136, 171, 181, 199, 208 and 320 among the services using this stretch.
  • If you drive to Croydon via Shirley, the A232 Wickham Road is going to 20mph in the same phase.
  • Inside the borough nothing changes yet. Neither the A21 London Road into Bromley town centre nor the A232 from West Wickham to Locksbottom is in phase 4.

For live closures on both red routes, see our Bromley roadworks and travel page.

Sources