New research[1] from engineering consultants, Future Transport, models the impact of capping speeds at 20mph vs. 30mph. This “real life” modelling that takes account of the stop/start nature of urban traffic yields a very different result from traditional steady-state models. It shows significant and substantial reductions in emissions: CO₂ lower by 26% and NOx 28% lower. With UK hosting COP26, campaigners are calling on governments to set 20mph or 30km/h limits as national urban/village defaults.

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

Air Quality, Covid-19 and How 20mph Limits Help Us To Breathe Easily

As a disease that dramatically affects our respiratory system it is hardly surprising that there is a link between the quality of air we breathe,  and our subsequent ability to cope with Covid-19. Here we discuss air quality and how it can be improved with an emergency national default 20mph urban limit.

20mph reduces the power imbalance between road users so some drivers can choose to drive less far or less often.  It also smooths traffic flow. Independent travel by the young and vulnerable groups rises too.

Reducing speed limits is the quickest, cheapest and most equitable way of cutting traffic noise. Slower is quieter.

Lower speeds also allow the noise benefits of electric cars to be spread more widely and are foundational for traffic reduction.

By Anna Semlyen, Cutting Your Car Use author, National Campaign Manager of 20’s Plenty for Us

Climate activists are ramping up direct action because scientists say we are running out of time for politicians to act before the 1.5-2 degree warming that is irreversible.  Top personal ways to decarbonise and prevent climate chaos are to stop eating meat and to stop flying.  20mph limits enter the climate debate as crucial to reduce fossil fuel use for transport in towns and villages. Politicians must act to make it more possible for citizens to ‘do their bit’ to get about the places they live in greener ways.

The Institute of Welsh Affairs in its recent report on “Decarbonising Transport in Wales”[1] has called for a default 20mph urban limit as a key recommendation to enable Wales to meet its projected energy demands entirely by 2035.

[1] http://www.iwa.wales/wp-content/uploads/2018/06/IWA_Decarbonising_Transport-1.pdf

Many people think that driving at 20mph lowers fuel economy. Yet research shows that for many cars a steady 20mph is the most efficient speed if you can keep it steady. Indeed at 20mph many cars will achieve fuel consumption better than 90mpg. But what changes things is in an urban environment where you are consistently slowing down for obstacles, lights, junction and congestion and then having to speed up again.

Here we explore the engineering principle behind the energy that gets used by a motor vehicle when moving.

20mph limits tackle many public health issues including street safety, physical exercise, obesity, coronary heart disease and more. Public Health staff are strongly encouraged to attend the 20’s Plenty for Healthier Places Conference on Weds 8^th March 2017. Health and slower speed experts will discuss best practice, innovation, research and cost effectiveness.  20mph limits are healthy and affordable.  Councillors set local speeds