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 jobs

Cyfarwyddwr Corfforaethol - Economi a’r Amgylchedd / Corporate Director Economy & Environment

Caerphilly County Borough Council
£117,115 - £130,128 p/a
Tîm Caerffili-YN WELL GYDA’N GILYDD Team Caerphilly- BETTER TOGETHER Caerphilly (Caerffili)
Recruiter: Caerphilly County Borough Council

Operations Manager (Traffic & Compliance)

Capita
Competitve
We’re looking for the right person for this role, so we don’t mind where you’re located, as long as... London (Greater)
Recruiter: Capita

Operations Manager (Traffic & Travel)

Capita
Competitve
You’ll be responsible for developing strategies and delivering projects and programmes as part of the service senior management team - including... London (Greater)
Recruiter: Capita

Operations Manager (Development Control)

Capita
Competitve
You’ll be responsible for the overall delivery of all highways and development control management in this varied role. London (Greater)
Recruiter: Capita

Operations Manager (Assets)

Capita
Competitve
It’s an exciting role where we’ll look to you to ensure highways projects are delivered against continuous improvement and... London (Greater)
Recruiter: Capita

Asset Manager

Capita
Competitve
You’ll be part of a friendly team and work closely with the operations managers and senior team to... London (Greater)
Recruiter: Capita

Technical Supervisor

Capita
Competitve
You’ll make an impact in a friendly team who are responsible for... London (Greater)
Recruiter: Capita

Traffic & Travel Manager

Capita
Competitve
As part of a friendly team, you’ll support the operations manager of traffic and travel in the overall delivery of... London (Greater)
Recruiter: Capita

Environmental Surveyor

The Royal Borough of Kensington & Chelsea Council
£34,900 - £47,300 per annum
You will have practical experience of grounds and repair works to common parts of housing estates and... Kensington and Chelsea, London (Greater)
Recruiter: The Royal Borough of Kensington & Chelsea Council

Traffic Engineer

Royal Borough of Greenwich
£25.137 - £34.209
We are looking to appoint a Traffic Engineer to work within the Traffic Group (Traffic Team) to
Recruiter: Royal Borough of Greenwich

Senior Travel Plan Officer

Somerset County Council
£25,991 to £29,577 per annum
Fantastic opportunity in Somerset to work in our Travel Plan Team within the Highways Development Management service as a... Somerset
Recruiter: Somerset County Council

Outdoor Learning Assistant

Kirklees Metropolitan Council
£11,036 per annum
You will contribute to the outdoor learning programme for a wide range of participants visiting our Centres. Kirklees, West Yorkshire
Recruiter: Kirklees Metropolitan Council

Director of Operations

St. Helens Metropolitan Borough Council
£92,968 - £98,282
This role is an opportunity for talented, corporate thinking and grounded leaders to grow personally and professionally in... St Helens, Merseyside
Recruiter: St. Helens Metropolitan Borough Council

Principal Traffic Management Engineer

City and County of Swansea Council
£38,890 to £42,821 per annum
You will enjoy an interesting and satisfying work-life with many opportunities to develop valuable skills and experience in the delivery of... Swansea (Abertawe)
Recruiter: City and County of Swansea Council

Refuse Driver (LGV Chargehand Driver)

Royal Borough of Greenwich
£22995 - £24258 per annum + plus contractual overtime and allowances
It is an exciting time in Waste and Street Services at the Royal Borough of Greenwich. This is a opportunity to be part of a busy, successful team mak England, London, Greenwich
Recruiter: Royal Borough of Greenwich

Principal Traffic Signal and ITS Engineer

Warwickshire County Council
£40,876.00 - £42,821.00 plus annual standby allowance of £2,562.84
You will be responsible for the day-to-day operation and maintenance of our Urban Traffic Management and Control System. Warwickshire
Recruiter: Warwickshire County Council

Refuse Driver

Royal Borough of Greenwich
£22.995 - £24.258
The successful candidates will work anywhere within the Borough of Greenwich, work outside in all weathers, and be able to use... Greenwich, London (Greater)
Recruiter: Royal Borough of Greenwich

Public Protection Group Leader

Kirklees Metropolitan Council
£43,857 - £45,859
You will develop a strategic approach to deliver a service which promotes jobs and businesses, protects the safety of... Kirklees, West Yorkshire
Recruiter: Kirklees Metropolitan Council

Project Officer - Air Quality

Kirklees Metropolitan Council
£27,741 - £30,451
We’re looking for an additional team member to support the Senior Environmental Health Officers in... Kirklees, West Yorkshire
Recruiter: Kirklees Metropolitan Council

Customer Support Officer

The Royal Borough of Kensington & Chelsea Council
£25,833 - £29,796 per annum
The successful candidate for this role will be someone who has great administration and customer service qualities, and... Kensington and Chelsea, London (Greater)
Recruiter: The Royal Borough of Kensington & Chelsea Council

Highways on Fridays

Register now!

Latest Issue

latest magazine issue
Also:
  • Highways Awards shortlist revealed
  • Jim O’Sullivan interview
  • Legalising e-scooters: risks and rewards
View the latest issue

Latest Video