20’s Plenty For Us is a not-for-profit organisation that campaigns for a speed limit of 20mph on streets where people and motor vehicles mix. Founder Rod King was awarded an MBE for Services to Road Safety in 2013.

Since the first city-wide implementation of a 20mph speed limit in the UK – in Portsmouth in 2006 – the campaign to reduce speeds in residential areas has snowballed.

Limits now cover the communities of over 28m UK citizens. This includes the whole of central London and over half of the largest 40 urban authorities, while the whole of Wales and Scotland will also soon implement 20mph limits. From our largest city to some of our smallest villages, the message that 20 is Plenty is being heard, loud and clear.

One of the people communicating that message, combining both a passion for road safety and irrefutable logic, is Rod King MBE, founder and campaign director for 20’s Plenty For Us. He has been tireless in campaigning for lower speeds, channelling a global trend in attempts to introduce 20mph (or 30kph) limits in areas where cars mix with people walking or cycling.

The benefits for society are clear, despite the difficulties in disentangling casualty and active travel statistics. As King says: “Generally speaking, casualties tend to come down by about 20%. A review of Edinburgh undertaken by St Andrews University was talking about a third. Other places – Calderdale, Bristol, Cheshire, Weston, Chester – all report 20-40% reductions in casualties on their roads.”

“What we've found is that 20mph limits are not so much a silver bullet, but a foundation. If you're looking at creating better infrastructure for cyclists, it becomes easier if you have a generic 20mph limit.”

King explains that the 20's Plenty movement is more about social engineering, in terms of building a public consensus, than traffic engineering. Instead of approaching road safety issues with site-specific solutions, we are moving more towards understanding how to make population-wide interventions that lower risk everywhere. And, in lowering risk everywhere, you lower the risk at conflict points.

20’s Plenty For Us advises communities wishing to introduce 20mph limits to demonstrate to local officials and councillors that it is a universal aspiration, by passing motions at parish councils, for example.

“The support for it can provide a context for officers and engineers to actually look at how the speed limits can be deployed,” King explained. “And now, compared to 2006, you can actually visit many places in the UK where 20mph has been introduced.”

Drivers will be pleased to hear that King doesn’t think that traffic calming measures such as speed humps are the best solution. “It's very expensive – around £60,000 per kilometre – compared with putting up signs, at about £1,100 per kilometre. For the same cost, you can physically calm one street with 250 people on it, or you can help 12,500 people by making the whole community a signed 20mph zone. I won't say signed only, because what we say is signed plus engagement.”

King advocates for limiting speeds across an entire community rather than using traffic calming measures within isolated zones – outside schools, for example – explaining that “you can't say, ‘slow down here, because it's important’ without implying, ‘speed up as soon as you are away from here’. A limit of 20mph with physical calming doesn't help beyond that area of physical calming.”

20mph speed limits currently cover 28m of the UK population but don’t bet against King and other road safety campaigners reaching the rest of the population over the coming years.

For more see the 20’s Plenty For Us website.

The annual conference and AGM for the Society of Road Safety Auditors (SoRSA) is an in-person event this year, taking place in Manchester on 20-21 June 2022.