Exclusive: Average speed cameras cut Welsh air pollution by half

14/10/2020 | RHODRI CLARK

Highways can reveal that air pollution at roadside hotspots reduced dramatically after the Welsh Government began enforcing lower speed limits with cameras.

The figures, obtained by a Freedom of Information request, show that pollution levels fell by almost half on some parts of the Welsh trunk road following the installation of average speed cameras.

The lessons may be valuable to Highways England as it trials reduced speed limits on sections of its network to bring Nitrogen Dioxide (NO2) concentrations within legal limits.

The Welsh Government introduced mandatory 50mph speed limits on five trunk-road sections in June 2018, specifically to reduce air pollution in neighbouring built-up areas.

Many drivers treated the limit as optional, even after the Government resorted to putting up signs explaining that slowing down would improve local air. Mean speeds through four of the sections ranged from 55mph to 58mph during the first year of the 50mph limits.

In summer 2019, average speed cameras and signs were installed. Now an FOI release reveals that NO2 concentrations beside the A470 between Upper Boat and Pontypridd were 82.0 μg/m3 in February 2018 and fell to 78.6 μg/m3 a year later (with the 50mph limit in place) but by February 2020 concentrations were just 43.2 μg/m3 – or 47.3% lower than in February 2018.

Data after February 2020 were not requested, to ensure comparisons were not influenced by COVID-19 travel restrictions.

From February 2018 to February 2020, other NO2 reductions were 41% on M4 J25-26 at Newport; 39.5% on M4 J41-42 at Port Talbot; 22.4% on A494 at Deeside; and 32.3% on A483 near Wrexham.

In all cases, the reduction mostly occurred after average speed cameras were installed.

In February 2020, more than 92% of vehicles complied with the 50mph speed limits at Port Talbot and Wrexham (both directions) and westbound at Deeside. The lowest compliance was 81.1% westbound at Pontypridd.

Compliance data for the M4 at Newport was not available.

Highways InProfile

latest magazine issue
Highways jobs

Project Lead - Bridges and Structures WMF3037e

£45,718 to £46,731
We are currently seeking to recruit a Project Lead to join our Bridges and Structures team Kendal, Cumbria
Recruiter: Westmorland and Furness Council

Traffic Management Technician - WMF3040e

£27,711 - £28,624
Are you an organised and motivated individual who wants to make a difference to how our roads are managed? Cumbria / Various
Recruiter: Westmorland and Furness Council

Traffic Management Officer - WMF2114e

£37,035 - £37,938
Are you an experienced and motivated professional looking to take the next step in your traffic management career? Cumbria / Various
Recruiter: Westmorland and Furness Council

Senior Transport Planner

£47,532 - £50,574
Royal Greenwich is a borough synonymous with first class modern services Greenwich, London (Greater)
Recruiter: Royal Borough of Greenwich

Technician - Highway Inspector

Grade 8 £28,797 - £30,708 per annum (Pay Award Pending)
Within the Highways Maintenance Team we are looking for an enthusiastic, customer focused and experienced person to join the Service Derbyshire
Recruiter: Derbyshire County Council

Project Delivery Senior Team Leader

£74,480 - £85,964
Are you an experienced Chartered Civil Engineer (or equivalent professional qualification) Glasgow City
Recruiter: Transport Scotland

Assistant Traffic Management Technician - WMF2104e

£25,584 - £25,992
Westmorland and Furness Council is seeking an organised and enthusiastic individual to join our South Lakeland team Kendal, Cumbria
Recruiter: Westmorland and Furness Council

Bulky Operative

£25,584.00 - £27,269.00, Grade 5, 37 hours, Permanent.
An opportunity exists in the Council’s Street Scene Services for a Bulky Operative Wakefield, West Yorkshire
Recruiter: Wakefield Council

Project Delivery Team Leader

£57,710 - £71,842
Are you an experienced Chartered Civil Engineer (or equivalent professional qualification). Glasgow City
Recruiter: Transport Scotland

Traffic Management Officer - WMF2102e

£37,035 - £37,938
This is a key role supporting the delivery a wide range of traffic and road safety schemes. Kendal, Cumbria
Recruiter: Westmorland and Furness Council

Shared Service Manager (Waste) North Herts Council

£52000 - £61000 per annum
Shared Service Manager (Waste) North Herts CouncilNorth Herts CouncilPermanent, Full Time£52,866 - £61,866 per annum, plus car allowance (pay award pe England, Hertfordshire, Letchworth Garden City
Recruiter: Essex County Council

Street Scene Protection Officer - Braintree District Council

£30000 - £34000 per annum
Street Scene Protection Officer - Braintree District CouncilBraintree District CouncilPermanent, Full Time£30,313 to £34,612 per annumLocation
Recruiter: Essex County Council

Traffic Management Officer - WMF2102e

£37,035 - £37,938
This is a key role supporting the delivery a wide range of traffic and road safety schemes. Kendal, Cumbria
Recruiter: Westmorland and Furness Council

Assistant Traffic Management Technician - WMF2104e

£25,584 - £25,992
This is a key support role, helping to deliver a wide range of traffic and road safety schemes across South Lakeland. Kendal, Cumbria
Recruiter: Westmorland and Furness Council

Flood Risk Engineering and Strategy Officer

£49,764 - £55,623
In line with our One Coventry Values, we want to ensure that our communities are represented across our workforce Coventry, West Midlands
Recruiter: Coventry City Council

Senior Integrated Transport Officer

£34,324 - £37,529
Are you an experienced transport planning professional ready to influence strategic policy and drive real change Matlock, Derbyshire
Recruiter: Derbyshire County Council

Roadworker Trainee LGV Driver (3 Posts)

Grade 6 £25,183 - £25,638 per annum (Pay award pending)
We’re looking for Roadworker/trainee LGV drivers to be part of our team undertaking major highway, bridge and related construction and reconstruction Derbyshire
Recruiter: Derbyshire County Council

Engineer

£44,430 - £51,663
This post is within the Highways Design and Delivery Team. London (Greater)
Recruiter: Tower Hamlets London Borough Council

Civil Enforcement Officer - WMF3013e

£27,711 -£28,624
Are you seeking an active and challenging role, part of a friendly and welcoming team? Cumbria / Various
Recruiter: Westmorland and Furness Council

UGO Bus Driver

Up to £25081.00 per annum
UGO Bus DriverPermanent, Part TimeUp to £25,081 per annum (full time equivalent)Location
Recruiter: Essex County Council
SUBSCRIBE NOW

Latest Video

Subscribe to Highways today to ensure you keep your finger on the pulse of everything happening in the UK road network throughout the year.

SUBSCRIBE NOW