Cornwall is one of the first rural areas to reduce speed limits from 30mph to 20mph on residential roads and in built-up areas. It will make roads, safer, healthier and greener for everyone.
After a successful pilot (Phase 1) in Camelford, Falmouth and Penryn during 2022, a countywide roll out programme has been approved.
Cornwall Council aims to reduce both death and serious injury by 50% on our roads by 2030, and 20mph limits will support this.
The benefits of reducing speeds to 20mph
Research provides a strong link between traffic speed and the severity of injury when a collision occurs. If someone is struck at 20mph they have a 90% chance of survival compared to a 50% chance if struck at 30mph.
Travelling at 20mph provides many other benefits too:
- Increasing child and adult activity levels. This will improve health and wellbeing.
- Providing a safer environment. This will encourage more people to walk and cycle.
- Supporting climate change declaration. This will include lower emissions and tackling congestion, as well as supporting our ambition to be Carbon Neutral by 2030.
- Creating a stronger sense of community as more people come together to use the space.
Walking and cycling
Villages, towns and cities should be places where people are free to travel in ways that are:
- Safe
- Sustainable
- Healthy
- Fair
Higher speeds negatively impact safety where people live, work and play. This particularly affects our more vulnerable road users such as children and the elderly.
Lower speeds improve both actual and perceived safety and may mean people feel more comfortable to walk and cycle. Children will also have a safer environment to walk to school and the elderly will feel more able to travel safely.
Lower speeds benefit air quality
There is little evidence to suggest that reducing vehicle speeds to 20mph increases pollution. It is not as straightforward as more time driving equals more pollution. Driving styles, acceleration and braking are all contributory factors to increased emissions. Other research has shown that up to 75% of road transport particulate emissions come from tyre and brake wear, not exhausts. Slower speeds encourage a smoother driving style, which ultimately decrease's emissions.
Research has found that reducing speeds from 30mph to 20mph reduced CO₂ emissions up to 37.8% and NOx emissions by 51.0%. This is while only having a minimum impact on journey times. The impact of different driving styles, vehicle size, and fuel type were also investigated and found to impact the results.
Journey times
Journey times on roads in urban areas tend to be determined by junctions, crossings and parked vehicles, rather than the speed limit. Often lowering the speed limit to 20mph will have little or no impact on journey times. Where there is an impact, this would be negligible, but in turn would make the roads safer for everyone; pedestrians and cyclists.
Bus journey times were reviewed during Phase 1 and were found to be negligible.
Less acceleration and braking smooths traffic flow, reduces gaps between cars and reduces idling.
Lower speeds benefit noise pollution
Noise research studies show about a 3 decibel (dB(A)) reduction when reducing a 30mph speed limit to 20mph. This is perceived as halving ambient noise.
The impact on fuel consumption
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 over twice as much energy as accelerating up to 20mph. A 20mph speed limit and a smooth driving style, can help avoid unnecessary speeding up and slowing down, saving fuel.
A study by the Transport Research Board identified that 30km/h zones (18.6mph) have a 12% reduction in fuel consumption.
Where 20mph won’t be introduced
We will review all roads on a case-by-case basis where the existing limit is 30mph, with the intention to reduce to 20mph. Urban areas with high pedestrian and cyclist movements will be prioritised. This could include areas around schools, shops, markets, playgrounds.
For some roads, it may be appropriate to keep 30mph or deliver a more focused 20mph section. This will be a considered decision, based on local circumstances. Exceptions will generally be major roads and where vehicles are the primary function.
An exceptions process and associated assessment criteria has been developed to help support this process.
Speed limits higher than 30mph will not qualify for 20mph. We appreciate that communities with speed limits of 40mph or above, may face difficulties. There may be opportunities to improve the local environment through other initiatives for example, the Community Highway Scheme.
Police enforcement
Devon and Cornwall Police will enforce 20mph limits in the new zones. Enforcement will be carried out in places where the new speeds are regularly being broken, and where there is a risk of injury to other road users. Road safety is something all road users have responsibility for. Road user respect and positive driver behaviour is crucial.
Whether you live in a 20mph or travel through 20mph, we ask you to respect those limits in place.
Timelines for the rollout of 20mph
Statutory public consultation will be undertaken for each phase of delivery.
Using road collision and casualty data we have identified the priority order for the rollout.
2023/24
- Camborne, Pool, Illogan and Redruth
- West Penwith
- Truro and the Roseland
2024/25
- Hayle and St Ives
- St Austell and Mevagissey
- Newquay and St Columb
- Cornwall Gateway
- Liskeard and Looe
- China Clay
2025/26
- Helston and South Kerrier
- Bude
- Launceston
2026/27
- Wadebridge and Padstow
- Bodmin
- Caradon
- St Blazey, Fowey and Lostwithiel
- St Agnes and Perranporth
