Islands are Ideal for 20mph limits

Islands are ideal places for slower speeds due to sea boundaries, less through traffic, attracting tourists and cyclists. Also aging and pockets of deprived populations that can hugely benefit from better safety.  20mph limits prevent 20% of casualties[1].

The first UK place to go wide-area 20mph limited through signage and light touch police enforcement was Portsmouth which is mainly on Portsea Island - a low-lying island of 10² miles - off the South coast.  Island community characteristics fit perfectly with successful implementations of 20mph speed limits including:


1)      No through traffic. A sea boundary means that through traffic is near zero – ie  few cross-over journeys between neighbouring authorities (with other speed limits). This improves driver compliance.

2)      Easily defined boundaries improves the success of marketing a slower speed message.  It’s easier to make the case at all island entry points, whether by sea or air, that 20mph limits are normal here.  Because of low through traffic and defined boundaries all drivers will all know that the limit is 20mph.

3)      A special case. Being unlike other places and having a lower speed limit is easier to ‘sell’ to islanders and visitors. they’d be more likely to agree with being a special case compared to mainland norms.

4)      Tourism. 20mph markedly improves a tourist’s experience and safety. Visitor numbers rise when a public realm has safer, calmer streets.  Jobs and wealth are key to success. Tourists like walking around to enjoy the views and ambience.  Some tourists are from countries where they drive on the right. This affects safety due to learnt habits of looking the wrong way.  20mph makes roads safer, quieter (by 50%) and more pleasant places to be[1], helping cycle tourism too.  Islander prosperity is often highly dependent on visitors. Tourist dependent places are choosing 20mph – like Oxford, York, Cambridge, Bath and Chester.

5)      Slower pace of life.  Island tourist staff are marketing a visitor experience with the unique selling point of a slower pace of life with beautiful, unspoilt, remoteness i.e. less hurried. An island holiday in a 20mph place is a child, family, cycling and older-people friendly option.

6)      Aging population This is due to factors like retiring to a seaside community and fewer births than main lands.  Older people benefit a hugely from 20mph as they take longer to cross the road, are more likely to be disabled or use mobility aids and have limited vision (especially in lower light).  Plus, older bones are brittle with recovery and survival likelihoods lower if injured.  Whilst, on average, people are 7 times more likely to survive a crash at 20mph rather than 30mph, for over 60 year old’s it is ten times safer[2].

7)      Deprived populations 20mph improves equality. There is evidence that the poor are most likely to be involved in crashes. Also if the tourist economy does well, it provides Islanders with much needed income.


Isle of Wight full Council voted to go 20mph limited in October 2016. 20’s Plenty for Us expect many more island communities to agree a 20mph norm.  20mph is already agreed by 50 local authorities and for 16m (25%) of people in the UK.

20’s Plenty for Us call on the residents and Councillors of Islands to embrace the huge benefits of 20mph limits and demand 20mph limits from their political leaders.

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