Lowering Speed Limits Programme

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The Mayor and Transport for London (TfL) are committed to Vision Zero, eliminating death and serious injury from London’s roads. The Vision Zero Action Plan 2 sets out our ambition and next steps to achieve this. It details our plans to reduce road danger, including proposals to implement safer speeds on the roads we operate and manage across London.


What we are doing

TfL manages the TfL Road Network (TLRN) which is made up of London’s most strategic roads, accounting for roughly 5% of London’s roads. The remaining 95% of London’s roads are managed by local authorities.

In our Vision Zero Action Plan 2, published in March 2026, we committed to ensuring speed limits on the TLRN are consistent, easy to comply with, and appropriate to the mix of road users and context. By 2025:

  • 20mph will be the default speed limit in central and inner London on the TLRN

  • We will reduce speed limits on TLRN roads where people live, take public transport, or there are side roads without traffic signals, to a default maximum speed limit of 40mph

To deliver this, TfL will lower the speed limit on at least a further 65km of the TfL Road Network by 2030, making over 80 per cent of its roads in central and inner London 20mph

It's also the policy of two thirds of London local authorities to apply a 20mph limit to most of their roads.

We are committed to improving transport in London by making it safe and reliable. All of our plans have been designed with this in mind. Please view our Equalities Statement for more information.

Our work consists of installing new traffic signing and relining the carriageway. The majority of works will be carried out under ‘mobile works’ with minimal impact to road users and pedestrians. In some cases, as a last resort, carriageway and footway closures will be utilised with diversions in place.


Why we are lowering speeds

Collision data from around the world is very clear. It shows the faster a vehicle is travelling, the more likely a collision will occur because the driver has less time to react, stop or avoid the collision and the more severe an injury resulting from the collision will be.

We recently published a study which examines the impact of over 150 20mph schemes on borough roads in London between 1989 and 2013. Our report – the first of its scale in London – comprehensively demonstrates that 20mph schemes have had a significant positive impact on reducing the number of people killed or seriously injured (KSI) on our roads. It shows that on borough roads where 20mph speed limits were introduced, there was a 34% reduction in the number of people killed or seriously injured (from 395 to 260), compared against the background trend of a 15% fall.


The effectiveness of the Lowering Speed Limits programme on the TLRN so far

Phase 1

Data collected from 1 May 2020 to 30 June 2022 were compared to a similar seasonally-matched period before 20mph speed limits were implemented in the central London Congestion Charging Zone in 2020. The number of collisions fell 25% (from 405 to 304), and collisions resulting in death or serious injury fell 24% (from 94 to 71).

Note - trends should be interpreted with caution because this analysis covers the period including the coronavirus pandemic which may have impacted trends in collisions. Similar analysis has been undertaken (.DOC 111 KB) to exploring the safety impacts of 20mph speed limits on borough roads from 1989 to 2013 which found a 32% reduction in collisions resulting in death or serious injury (from 371 to 252) on 20mph roads compared to a 15% fall in collisions resulting in death or serious injury in the control group (all borough roads within the Greater London Authority area).

The London-wide reduction in collisions resulting in death or serious injury fell around 10% over the same period.

Collision data for the whole of London is provided in CSV extracts on our website every year. See the Road safety data page.

Phase 2

Detailed analysis will be published after three years’ worth of collision data becomes available.

The Mayor and Transport for London (TfL) are committed to Vision Zero, eliminating death and serious injury from London’s roads. The Vision Zero Action Plan 2 sets out our ambition and next steps to achieve this. It details our plans to reduce road danger, including proposals to implement safer speeds on the roads we operate and manage across London.


What we are doing

TfL manages the TfL Road Network (TLRN) which is made up of London’s most strategic roads, accounting for roughly 5% of London’s roads. The remaining 95% of London’s roads are managed by local authorities.

In our Vision Zero Action Plan 2, published in March 2026, we committed to ensuring speed limits on the TLRN are consistent, easy to comply with, and appropriate to the mix of road users and context. By 2025:

  • 20mph will be the default speed limit in central and inner London on the TLRN

  • We will reduce speed limits on TLRN roads where people live, take public transport, or there are side roads without traffic signals, to a default maximum speed limit of 40mph

To deliver this, TfL will lower the speed limit on at least a further 65km of the TfL Road Network by 2030, making over 80 per cent of its roads in central and inner London 20mph

It's also the policy of two thirds of London local authorities to apply a 20mph limit to most of their roads.

We are committed to improving transport in London by making it safe and reliable. All of our plans have been designed with this in mind. Please view our Equalities Statement for more information.

Our work consists of installing new traffic signing and relining the carriageway. The majority of works will be carried out under ‘mobile works’ with minimal impact to road users and pedestrians. In some cases, as a last resort, carriageway and footway closures will be utilised with diversions in place.


Why we are lowering speeds

Collision data from around the world is very clear. It shows the faster a vehicle is travelling, the more likely a collision will occur because the driver has less time to react, stop or avoid the collision and the more severe an injury resulting from the collision will be.

We recently published a study which examines the impact of over 150 20mph schemes on borough roads in London between 1989 and 2013. Our report – the first of its scale in London – comprehensively demonstrates that 20mph schemes have had a significant positive impact on reducing the number of people killed or seriously injured (KSI) on our roads. It shows that on borough roads where 20mph speed limits were introduced, there was a 34% reduction in the number of people killed or seriously injured (from 395 to 260), compared against the background trend of a 15% fall.


The effectiveness of the Lowering Speed Limits programme on the TLRN so far

Phase 1

Data collected from 1 May 2020 to 30 June 2022 were compared to a similar seasonally-matched period before 20mph speed limits were implemented in the central London Congestion Charging Zone in 2020. The number of collisions fell 25% (from 405 to 304), and collisions resulting in death or serious injury fell 24% (from 94 to 71).

Note - trends should be interpreted with caution because this analysis covers the period including the coronavirus pandemic which may have impacted trends in collisions. Similar analysis has been undertaken (.DOC 111 KB) to exploring the safety impacts of 20mph speed limits on borough roads from 1989 to 2013 which found a 32% reduction in collisions resulting in death or serious injury (from 371 to 252) on 20mph roads compared to a 15% fall in collisions resulting in death or serious injury in the control group (all borough roads within the Greater London Authority area).

The London-wide reduction in collisions resulting in death or serious injury fell around 10% over the same period.

Collision data for the whole of London is provided in CSV extracts on our website every year. See the Road safety data page.

Phase 2

Detailed analysis will be published after three years’ worth of collision data becomes available.

Page last updated: 03 Aug 2026, 03:34 PM