New data from Transport for London echoes what 20’s Plenty have been finding in recent 20mph implementations - that speed reductions on major and faster roads are resulting in substantial reductions in speeds and casualties for vulnerable road user casualties. TfL has just published research into the impact of the introduction of 20mph limits across a range of sites on the roads that it controls (typically London's arterial roads - the "Red Routes") which shows that, after speed limits were lowered, collisions involving a vulnerable road user have decreased by 36% (from 453 to 290), while collisions resulting in death or serious injury have decreased by 25% (from 94 to 71). The number of collisions involving people walking have decreased by 63% (from 124 to 46).
The data is clear from authorities as varied as London to the Scottish Borders that setting 20mph limits on faster and more major routes is disproportionately beneficial. When Scottish Borders Council set most of its 30mph roads to 20mph it found the largest reductions in speed on the faster main roads through towns and villages. This endorses the setting of 20mph as a norm for all built-up areas rather than just where average speeds are already low.
The significance for governments in Wales and Scotland, who are setting 20mph as an urban/village norm, is that main roads which are shared with pedestrians and cyclists should be included unless there is “robust and evidenced application of local factors indicating otherwise”. Such guidance for exceptions to a 20mph urban/village default is included in the Welsh Government guidance for its’ national 20mph limit that becomes effective on 17th September 2023. It also aligns with the best practice Stockholm Declaration on speed limits.
Jeremy Leach, London Campaign Co-ordinator for 20's Plenty for Us said:
"This research underlines once again the importance of reducing vehicle speeds to a maximum of 20mph in built-up areas. Injuries are reduced and more people can feel safe to walk and cycle. TfL is right to be rolling out more 20mph limits on the roads that it manages and to be calling for the default speed limit on all residential roads in London to be changed to 20mph.”
Rod King MBE, Founder of 20’s Plenty for us commented :
“All over the world authorities are finding that 20mph limits deliver lower speeds, lower casualties and more pleasant places to live. Authorities with a population of 28 million people in the UK have already said that 20’s Plenty where people live, play, work, learn and shop. The current 30mph national limit for England is clearly no longer fit-for-purpose. With 79,000 casualties on England’s 30mph roads in 2019 (26,500 being pedestrians and cyclists), it’s time for the UK government to set a national default 20mph urban/village limit with exceptions only where evidentially safe for vulnerable road users. The benefits would transform the safety and livability of our communities.”
 TfL Press Release https://tfl-newsroom.prgloo.com/news/tfl-press-release-new-data-showssignificantimprovements-in-road-safety-in-london-since-introduction-of20mphspeed-limits
 Welsh exceptions guidance https://www.gov.wales/setting-exceptions-20mph-default-speed-limit-restricted-roads-html
 Stockholm Declaration – Resolution 11 https://www.roadsafetysweden.com/contentassets/b37f0951c837443eb9661668d5be439e/stockholm-declaration-english.pdf