20's Plenty

Why 20’s plenty - The case for 20 mph limits.

20 mph limits – an inexpensive and popular way to improve safety, cut pollution and encourage smarter travel choices.

There are over two hundred local campaigns in existence.  The department of Transport has published guidelines supporting 20mph limits in residential areas.


Popularity – 73% of drivers support 20mph speed limits on residential streets.  (British Social Attitudes Survey 2012)

Environment, Pollution, Climate Change, Air Quality- When 30 km/h (18.5 mph) zones were introduced in Germany, car drivers changed gear 12% less often, braked 14% less often and required 12% less fuel.  More walk and cycle.

Saves Time– 20mph makes traffic smoother, gaps between cars decrease, it’s easier to merge.  This means a more efficient flow of traffic than 30mph in urban areas.

20mph Limits cost 50 Times Less Than Zones– DfT Guidelines (1/06) relaxed requirements for 20 mph in residential areas.  It is no longer mandatory to impose physical measures such as bumps.  Current Local Authority costs are about £3 per head of population. 

Self- Enforcing– 20mph speed limits are community led and establishment endorsed.  Strong support from communities and an increasing police focus in community policing supports 20mph limits which can be enforced with a “light touch”

Economic Impact– At 20mph the gap between vehicles shortens, leading to improved traffic flow.  Shopping on foot is more pleasant.  House values rise.

Health Improvements– Reduced local emissions, improved air quality and a shift of some drivers towards more active modes of transport like walking or cycling.

Better Quality of Life and Reduced Ineqaulities– Slower speeds benefit large numbers of non-car users, reducing noise and allowing better urban design standards for quality places.  Those currently suffering the greatest inequalities tend to live nearer to busy roads and therefore benefit more from 20 mph limits.