An analysis of seven 20mph area shows how Local Authorities that include faster roads in signed-only schemes reap the most benefit:

1. Mean speed reductions of twice the previous estimate;
2. Greatest reductions on previously faster roads;
3. Close correlation between pre-existing speeds and speed reductions; and
4. Including faster roads brings much greater road casualty reductions.

Use our calculator to see the casualty reductions and financial benefits from implementing 20mph for your Local Authority. 

A nearly universal aspiration in communities is to make traffic speed compatible with community life and human survivability.  A 30mph limit is no longer fit for purpose for urban and village streets. Lower default limits are being set. Choose 20mph.

Among urban and village improvement options, 20mph ranks top for cost effectiveness. Over a wide area, 20mph benefits all road users and the whole community. Casualties fall 20%[1], noise almost halves and active travel rises. Councils can afford it.

[1] http://www.20splenty.org/20mph_casualty_reduction

A guest blog from Adrian Berendt of 20's Plenty for Kent and Campaigner of the year - 2018

Introduction

Road safety professionals often prefer targeting road safety improvements on particularly dangerous roads and junctions? Others consider it better to make more general interventions with a wider impact, known as the ‘prevention paradox’, e.g. health impact of immunisation.

We assess which approach is better by comparing two alternative approaches[1].

1) Targeted interventions on rural A roads. We use the example of the £100m fund for specific interventions as proposed by the UK government; and

2) Prevention Paradox – lowering overall speeds by a few miles per hour with wide area 20mph on urban non-A roads.

Our analysis shows that spending the same money on Alternative 2, the “Prevention Paradox” saves 5 times the number of KSIs as targeted rural A road interventions.

[1] We eliminated three other road types as potential candidates:

• Motorways: few casualties and atypical of the UK road network;
• Rural non-A roads: extensive, carry little traffic and have few casualties; and
• Urban A roads: mixed characteristics of each of the road types chosen; might need a combination measures.

Jesse Norman MP, the Minister for Transport has written to Councils saying the “WS Atkins report confirms public support for 20mph”.  Many Local Authorities are now reviewing 20mph policies and re-interpreting DfT guidance.

20’s Plenty for Us welcomes the publication of the long-awaited DfT Evaluation of 20mph limits. It confirms the public support and acceptance of 20mph limits but has failed to meet the original DfT objectives or provide increased evidence on how to make our streets safer.

For some it could seem counterintuitive to applaud a network-wide 1-2mph speed reduction. However, wide 20mph limits are highly cost effective. What seems, at first, like a small reduction in speeds benefits society at large. Shared gains add up. Wide 20mph limits are efficient, affordable, cost-effective, fair, understandable, rapid to install and healthy.

20mph limits are proven to prevent road injury, and reduce fear, fumes, noise and loneliness. Like universal vaccination, 20mph limits cost effectively raise public health in built up areas - due to less danger and greater physical exercise. Not to bring in 20mph could be grossly negligent. 

With the majority of largest 40 urban authorities adopting 20mph as the limit for most roads, isn’t it time we just put limit repeater reminders on the 30mph roads? This would hugely reduce costs and enable wider implementation in line with community and government objectives.