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Guidance on why we are introducing a 20mph speed limit.

First published:
8 July 2021
Last updated:

Why do you want to introduce a 20mph speed limit on residential roads and busy pedestrian streets across Wales?

Introducing a 20mph default speed limit on residential roads and busy pedestrian streets across Wales will:

  • save lives and reduce the risk and severity of injuries from collisions between vehicles and vulnerable road users
  • make streets safer for playing, walking and cycling
  • encourage more people to make more sustainable travel choices
  • makes Wales more attractive for our communities
  • bring physical and mental health benefits
  • reduce noise pollution, promote cleaner air and will be better for the environment
     

The legislation was approved by the Senedd in July this year.

Will this affect all roads that are currently 30mph?

The new legislation will make the default speed limit 20mph. This will leave local authorities and the 2 Trunk Road Agencies who are best placed to engage with the local community to decide which roads should remain at 30mph.

My local area already has reduced speeds of 20mph. Is it part of the Welsh Government initiative?

Many local authorities have already introduced 20mph speed limits across the country due to the recognised benefits and public support. As part of the first phase of  the 20mph rollout  8 settlements chose to take part and make their default speed lower: 

  • Abergavenny and Severnside, Monmouthshire
  • north Cardiff
  • Buckley, Flintshire
  • Cilfrew Village, Neath and Port Talbot
  • St Dogmaels, Pembrokeshire
  • St Brides Major, Vale of Glamorgan
  • Llanelli North, Carmarthenshire

Will the police enforce the proposed 20mph speed limit?

The police will continue to enforce all roads. We have been working closely with the police to develop an enforcement strategy which we believe makes our roads safer for all users. We are currently trialling enforcement in the first phase, ahead of the 20mph national implementation in September 2023.

Will reducing the speed limit impact traffic flow?

We do not believe that a 20mph speed limit will increase the number of vehicles driving on the road. Potentially traffic will flow more smoothly.

How will a lower speed limit promote walking and cycling?

Lower speeds mean that people feel more comfortable to walk and cycle and it is safer for children to walk to school. Older people, disabled people or people with additional needs will feel more able to travel independently.

There is evidence from across the world that vehicle speeds are the main reason why people do not walk or cycle or do not allow their children to walk or cycle to school.

How will the new 20mph limit affect pollution?

A study by Imperial College found that 20mph limited areas were “pollution neutral”. Many things contribute to pollution levels. They include:

  • driving style,
  • acceleration,
  • braking,
  • vehicle condition
  • distance travelled and
  • engine temperature.

We believe the lower speed limits will encourage more people to choose active ways to travel and there will be fewer polluting cars on the roads.

Will a reduced speed limit improve safety?

The World Health Organisation states that the most effective way to improve pedestrian safety is to reduce the speed of vehicles.

The Royal Society for the Prevention of Accidents (RoSPA) states that 45% of pedestrians are killed when struck by a car going at 30mph or less but only 5% when going at 20mph or less. In the distance a 20mph car can stop, a 30mph car will still be doing 24mph.

What effect will the speed limit have on journey times?

Journey times on roads in urban areas tend to be determined by junctions and signals, rather than the speed limit.

In many cases lowering the speed limit to 20mph will have little or no impact on journey times. Where there is an impact, our analysis showed us that most journeys would only be around 1 minute longer but this would make the roads safer for pedestrians and cyclists.

Why can’t the 20mph limit be set up as timed limits during school hours only?

This won't encourage children to walk or cycle from home, as it would only protect children near the school, where they already have safety in numbers.

80% of child casualties are on non-school trips. Introducing a 20mph default speed limit will make children safer from the moment they leave home - it is designed to make streets safer for everyone.

Will the roll out involve money being spent on speed bumps?

There is no plan to include traffic calming (including speed bumps) as part of the change to speed limits. There are other ‘softer’ measures that might be introduced, such as using buffer speed limits, removing the centre line, narrowing the carriageway visually, using planting etc.

Will reducing speeds to 20mph damage my car gear box?

Modern cars can drive at 20mph without damaging the engine or components. 20mph limits have been used since the early 1990s and there have been no reported gearbox issues. Using too low a gear at any speed may increase wear on gearboxes.

Using the right gear and driving at a consistent speed will help prolong engine and gearbox life.

Will driving at 20mph mean I use more fuel?

No. Fuel consumption is mainly influenced by the way we drive – driving at a consistent speed is better than stopping and starting. Accelerating up to 30mph can take twice as much energy as speeding up to 20mph.

Why are bicycles allowed to overtake me when I am driving at 20mph?

It is very rare for a cyclist to over-take a motorist at 20mph.

Speed limits in the Road Traffic Regulations and the Highway Code apply to motor vehicles only and not to bicycles. However, the Highway Code states that cyclists should be considerate of other road users.

Where else have 20mph speed limits been introduced in the UK?

20mph speed limits are in force in many of the medium and larger cities in England and Scotland and more rural authorities are introducing larger scale extended 20mph programmes.

If Scotland also sets 20mph default speed limits, up to 28 million people in the UK will live in local authorities where 20mph is normal.