Air quality reports

Improving air quality on and around our network

Air quality reports

We are working with the government to help improve air quality in the England by reducing Nitrogen Dioxide (NO2) levels and supporting the delivery of the UK NO2 Plan.

The government’s Pollution Climate Mapping (PCM) model identifies roads that might exceed the legal limits for air pollution at 40µg/m³.

Some of the roads the PCM has identified are part of our strategic road network (SRN) in England.

We've created a map that shows:

  • these locations on our Strategic Road Network
  • our latest understanding of the ambient concentrations near these links compared to the annual mean NO2 limit value

The map also shows:

  • the locations of automatic air quality monitors on our road network
  • the annual mean NO2 concentrations recorded by these monitors

The government has asked us to:

  • look closely at the areas where air pollution might be too high
  • put in measures to reduce pollution as quickly as possible in places where it does go over the legal limits

Air Quality – Annual Evaluation Reports

In response, we published a series of detailed assessment reports, which describe the work we have to do and report on the air quality alongside our network.

For areas where pollution is above the legal limit, we review air quality every year. This helps us see if the NO2 levels have reduced and if the steps we’ve taken are making a difference.

Air Quality - Annual Evaluation report 2023 (published October 2024)

Our Air Quality Annual Evaluation Report for 2023, published in our Annual Report and Accounts 2024, shows an improving picture of air quality alongside our network.

Initially, we reviewed 128 sections of our network where air quality was identified as at risk of exceeding legal limits. Over the last five years, our work to improve air quality means that over 90 of those sections are now below the legal limit.

In 2022, we reduced 8 more sections of our network to below the legal NO2 limit and our latest report for 2023 shows we have reduced another 10 to below the legal limit.

Strategic Road Network PCM link status reported in 2022 and 2023 Annual Evaluation Reports.

Strategic Road Network PCM link status  Number of Strategic Road Network links based on the reported outcome - Annual Evaluation Report 2022 Number of Strategic Road Network links based on the reported outcome - Annual Evaluation Report 2023
Above the limit value 30 20
Between 36-39.9µg/m³ 14 14
Air Quality – Annual Evaluation Report 2022 (published February 2024)

This evaluation report provides a summary of the latest compliance status for sections of the SRN that have been assessed for air quality by National Highways up to the end of 2022.

This report also provides an update on the progress of measures that have been implemented to improve air quality on these links during this time.

Evidence in the report shows that speed limits that have been in place to help manage air quality at two locations on the motorway network can be removed.

Air Quality – Annual Evaluation Report 2022 (published February 2024)

Air Quality Progress Update Report (July 2021)

Our assessment for each commission is summarised in this Air Quality Update Progress Report.

The report explains:

  • the outcome of the phased assessment approach
  • which links we assessed as meeting the NO2 limit value
  • the actions to achieve compliance on those sites exceeding the NO2 limit value.

National Highways Air Quality Monitoring Network (NHAQMN) reports

These reports give summary results from our air quality monitoring network since its creation in 2016.

We operate a network of automatic monitoring stations across the Strategic Road Network.

Data from these monitors helps us understand Nitrogen Dioxide and, more recently, particulate matter around our network.

Particulate matter (PM) means microscopic solid or liquid particles suspended in the air. These particles are categorised by size - for example, PM2.5 means particles with a diameter of less than 2.5 micrometres (µm). PM caused by road traffic includes exhaust emissions as well as tyre and brake wear.

This data informs our programme of activity to improve air quality.

If you need help interpreting this information, or more detailed data from a specific monitor, please contact us at Airquality@highwaysengland.co.uk.

Supporting technical information

Here are the technical reports covering our assessment of the PCM links on our network.

As we progress through each phase we update baseline maps and audit reports to include our findings from earlier phases.

If you need help interpreting  this information, or to track down a particular document, please contact us at Airquality@highwaysengland.co.uk.

Commission 1

Going through to Phase 3 - indicative modelling suggests compliance


Audit Summary Report – 8348
Audit Summary Report – 16237
Audit Summary Report – 18061
Audit Summary Report – 26064
Audit Summary Report – 28018
Audit Summary Report – 28445
Audit Summary Report – 36296
Audit Summary Report – 47243
Audit Summary Report – 47964
Audit Summary Report – 56009
Audit Summary Report – 56058
Audit Summary Report – 57783
Audit Summary Report – 70007
Audit Summary Report – 73998
Audit Summary Report – 74456
Audit Summary Report – 74590
Audit Summary Report – 75235
Audit Summary Report – 75258
Audit Summary Report – 75259
Audit Summary Report – 75290
Audit Summary Report – 75422
Audit Summary Report – 77419
Audit Summary Report – 77484
Audit Summary Report – 80428
Audit Summary Report – 81006
Audit Summary Report – 81374
Audit Summary Report – 81388
Audit Summary Report – 99331
Audit Summary Report – 99332
Audit Summary Report – 99333
Audit Summary Report – 99335

Indicative modelling suggests compliance (without monitoring support)

Audit Summary Report – 8147
Audit Summary Report – 17961
Audit Summary Report – 26051
Audit Summary Report – 38230
Audit Summary Report – 46062
Audit Summary Report – 48707
Audit Summary Report – 56062

Indicative modelling suggests exceedance

Audit Summary Report – 6046
Audit Summary Report – 26017
Audit Summary Report – 27711
Audit Summary Report – 28015
Audit Summary Report – 28361
Audit Summary Report – 28772
Audit Summary Report – 36045
Audit Summary Report – 36063
Audit Summary Report – 56063
Audit Summary Report – 57832
Audit Summary Report – 70230
Audit Summary Report – 73318
Audit Summary Report – 73424
Audit Summary Report – 73773
Audit Summary Report – 73920
Audit Summary Report – 77006
Audit Summary Report – 77007
Audit Summary Report – 81007
Audit Summary Report – 81008
Audit Summary Report – 81178
Audit Summary Report – 99614
Audit Summary Report – 99631

Nottingham compliant – stop at Phase 2

Audit Summary Report – 17304 Nottingham
Audit Summary Report – 37416 Nottingham
Audit Summary Report – 56557 Nottingham

 

Going through to Phase 3 - indicative modelling suggests compliance 

PCM Link Details_8348 - Leeds
PCM Link Details_16237 – East Hampshire
PCM Link Details_18061 - Plymouth
PCM Link Details_ 26064 - Kirklees
PCM Link Details_ 28018 - Southampton
PCM Link Details_28445 - Haslingden
PCM Link Details_36296 - Havant
PCM Link Details_47243 – Newcastle Under Lyme
PCM Link Details_47964 - Haslingden
PCM Link Details_56009 - Leeds
PCM Link Details_56058 – Test Valley
PCM Link Details_57783 – Stoke-on-Trent
PCM Link Details_70007 – Stockton on Tees
PCM Link Details_73998 - Wiltshire
PCM Link Details_74456 - Derby
PCM Link Details_74590 - Oldham
PCM Link Details_ 75235 - Manchester
PCM Link Details_75258 - Southampton
PCM Link Details_75259 - Southampton
PCM Link Details_75290 - Sefton
PCM Link Details_75422 – Stoke-on-Trent
PCM Link Details_77419 - Northampton
PCM Link Details_77484 - Stafford
PCM Link Details_80428 - Gateshead
PCM Link Details_81006 - Durham
PCM Link Details_81374 - Plymouth
PCM Link Details_81388 - Leeds
PCM Link Details_99331 – Stoke-on-Trent
PCM Link Details_99332 – Stoke-on-Trent
PCM Link Details_99333 – Stoke-on-Trent
PCM Link Details_99335 – Stoke-on-Trent

Indicative modelling suggests compliance (without monitoring support)

PCM Link Details_8147 – Stoke-on-Trent
PCM Link Details_17961 – Stockton on Tees
PCM Link Details_26051 - Bolton
PCM Link Details_38230 – Stoke-on-Trent
PCM Link Details_46062 - Durham
PCM Link Details_48707 – Newcastle Upon Tyne
PCM Link Details_56062 – Cheshire West and Chester

Indicative modelling suggests exceedance 

PCM Link Details_6046 - Manchester
PCM Link Details_26017 - Dudley
PCM Link Details_27711 – West Midlands
PCM Link Details_28015 - Salford
PCM Link Details_28361 - Hull
PCM Link Details_28772 – Newcastle upon Tyne
PCM Link Details_36045 - Manchester
PCM Link Details_36063 – Cheshire West and Chester
PCM Link Details_56063 - Leeds
PCM Link Details_57832 - Hull
PCM Link Details_70230 - Birmingham
PCM Link Details_73318 - Rugby
PCM Link Details_73424 - Sandwell
PCM Link Details_73773 - Stockport
PCM Link Details_73920 - Sandwell
PCM Link Details_77006 - Oldham
PCM Link Details_77007 - Oldham
PCM Link Details_81007 - Durham
PCM Link Details_81008 - Durham
PCM Link Details_81178 – Stockton-on-Tees
PCM Link Details_99614 - Manchester
PCM Link Details_99631 - Portsmouth

Nottingham compliant – stop at Phase 2

PCM Link Details – 17304 Nottingham
PCM Link Details – 37416 Nottingham
PCM Link Details – 56557 Nottingham

The Phase 3 (Commission No. 1) report builds on the work completed to date. The report presents updated air quality modelling, new air quality monitoring data and comes to a conclusion for each section of the Strategic Road Network (SRN) whether they exceed the annual mean nitrogen dioxide (NO2) limit value or not and the date compliance would be achieved. For those sections which have been identified as above the annual mean NO2 limit value a range of measures have been considered and where they can be delivered the report sets out the anticipated reduction in NO2 concentrations. 

Commission 1 Phase 3 Air Quality Report

Following completion of the Phase 3 assessment (Commission No. 1), the Joint Air Quality Unit (JAQU) asked National Highways to undertake a sensitivity analysis for 37 sections of the Strategic Road Network (SRN) using a different air quality model and the latest vehicle emission factors. The sections of road identified by JAQU had previously been modelled as just below the annual mean nitrogen dioxide (NO2) limit value of 40ug/m3. The purpose of the sensitivity test was to check if the previous modelled outcomes remain below the limit value and JAQU could be confident in approving all the findings in the Phase 3 assessment. 

The report showed the updated modelling had very similar outcomes to the air quality assessment previously shared in the original Phase 3 assessment (Commission No. 1) with JAQU. This meant there was no change to the original findings set out in the repor

Final Phase 3 Addendum Report - 37 links

PCM Link Details_16050 - M602 Salford
PCM Link Details_16237 - A3 East Hampshire
PCM Link Details_17736 - A3 Guildford
PCM Link Details_17961 - A19 Stockton-on-Tees
PCM Link Details_18061 - A38 Plymouth
PCM Link Details_26012 - M4 Hounslow
PCM Link Details_26017 - M5 Dudley
PCM Link Details_26051 - M61 Bolton
PCM Link Details_26064 - M606 Kirklees
PCM Link Details_27711 - A4123 West Midlands
PCM Link Details_27932 - A63 Hull
PCM Link Details_28015 - M602 Salford
PCM Link Details_28018 - M27 Southampton
PCM Link Details_28076 - A316 Spelthorne
PCM Link Details_28361 - A63 Hull
PCM Link Details_28445 - A56 Haslingden
PCM Link Details_28772 - A1 Newcastle upon Tyne
PCM Link Details_28776 - A1 Gateshead
PCM Link Details_36007 - M1 Rotherham
PCM Link Details_36063 - M53 Cheshire West and Chester
PCM Link Details_36296 - A27 Havant
PCM Link Details_38230 - A500 Stoke-on-Trent
PCM Link Details_46015 - M5 West Midlands
PCM Link Details_46062 - A1(M) Durham
PCM Link Details_47243 - A500 Newcastle-under-Lyme
PCM Link Details_47892 - M4 Hounslow
PCM Link Details_48331 - A63 Hull
PCM Link Details_48707 - A1 Newcastle upon Tyne
PCM Link Details_56007 - M621 Leeds
PCM Link Details_56009 - M621 Leeds
PCM Link Details_56033 - M32 Bristol
PCM Link Details_56062 - M53 Cheshire West and Chester
PCM Link Details_56063 - M621 Leeds
PCM Link Details_57767 - A38 Derby
PCM Link Details_57783 - A500 Stoke-on-Trent
PCM Link Details_57832 - A63 Hull
PCM Link Details_6013 - M4 Hillingdon
PCM Link Details_6046 - M56 Manchester
PCM Link Details_70007 - A66 Stockton-on-Tees
PCM Link Details_70206 - M11 Redbridge
PCM Link Details_70230 - M6 Birmingham
PCM Link Details_70271 - M56 Manchester
PCM Link Details_73318 - M6 Rugby
PCM Link Details_73424 - M5 Sandwell
PCM Link Details_73773 - M56 Stockport
PCM Link Details_73920 - M5 Sandwell
PCM Link Details_73998 - M4 Wiltshire
PCM Link Details_74456 - A38 Derby
PCM Link Details_74590 - M60 Oldham
PCM Link Details_74768 - M32 Bristol
PCM Link Details_75235 - A5103 Manchester
PCM Link Details_75258 - M27 Southampton
PCM Link Details_75259 - M27 Southampton
PCM Link Details_75290 - A59 Sefton
PCM Link Details_75422 - A50 Stoke-on-Trent
PCM Link Details_77007 - M60 Oldham
PCM Link Details_77419 - A45 Northampton
PCM Link Details_77436 - A34 Oxford
PCM Link Details_77484 - A50 Stafford
PCM Link Details_80427 - A1 Gateshead
PCM Link Details_80428 - A1 Gateshead
PCM Link Details_80846 - A282 Thurrock
PCM Link Details_81006 - A19 Durham
PCM Link Details_81007 - A19 Durham
PCM Link Details_81008 - A19 Durham
PCM Link Details_81178 - A66 Stockton-on-Tees
PCM Link Details_81374 - A38 Plymouth
PCM Link Details_81388 - M621 Leeds
PCM Link Details_8147 - A500 Stoke-on-Trent
PCM Link Details_8340 - A500 Stoke-on-Trent
PCM Link Details_8348 - M621 Leeds
PCM Link Details_99329 - A50 Stoke-on-Trent
PCM Link Details_99331 - A50 Stoke-on-Trent
PCM Link Details_99332 - A50 Stoke-on-Trent
PCM Link Details_99333 - A50 Stoke-on-Trent
PCM Link Details_99335 - A50 Stoke-on-Trent
PCM Link Details_99337 - A50 Stoke-on-Trent
PCM Link Details_99614 - M60 Manchester
PCM Link Details_99631 - A27 Portsmouth

Receptor Location Map_16050 — M602 Manchester
Receptor Location Map_16237 — A3 East Hampshire
Receptor Location Map_17736 — A3 Guildford
Receptor Location Map_17961 — A19 Stockton-on-Tees
Receptor Location Map_18061 — A38 Plymouth
Receptor Location Map_26012 — M4 Hounslow
Receptor Location Map_26017 — M5 Dudley
Receptor Location Map_ 26051 — M61 Bolton
Receptor Location Map_ 26064 — M606 Kirklees
Receptor Location Map_27711 — A4123 West Midlands
Receptor Location Map_ 27932 — A63 Hull
Receptor Location Map_28015 — M602 Manchester
Receptor Location Map_28018 — M27 Southampton
Receptor Location Map_28076 — A316 Spelthorne
Receptor Location Map_28361 — A63 Hull
Receptor Location Map_28445 — A56 Haslingden
Receptor Location Map_28772 — A1 Newcastle upon Tyne
Receptor Location Map_28776 E — A1 Gateshead
Receptor Location Map_36007 — M1 Rotherham
Receptor Location Map_36063 — M52 Cheshire West and Chester
Receptor Location Map_36296 — A27 Havant
Receptor Location Map_38230 C — A500 Stoke-on-Trent
Receptor Location Map_46015 C — M5 West Midlands
Receptor Location Map_46062 — A1(M) Durham
Receptor Location Map_47243 — A500 Newcastle-under-Lyme
Receptor Location Map_47892 — M4 Hounslow
Receptor Location Map_48331 — A63 Hull
Receptor Location Map_48707 — A1 Newcastle upon Tyne
Receptor Location Map_56007 — M621 Leeds
Receptor Location Map_56009 C — M621 Leeds
Receptor Location Map_56033 — M32 Bristol
Receptor Location Map_56062 — M53 Cheshire West and Chester
Receptor Location Map_56063 D — M621 Leeds
Receptor Location Map_57767 — A38 Derby
Receptor Location Map_57783 — A500 Stoke-on-Trent
Receptor Location Map_57832 — A63 Hull
Receptor Location Map_6013 — M4 Hillingdon
Receptor Location Map_6046 A — M56 Manchester
Receptor Location Map_70007 — A66 Stockton-on-Tees
Receptor Location Map_70206 — M11 Redbridge
Receptor Location Map_70230 — M6 Birmingham
Receptor Location Map_70271 — M56 Manchester
Receptor Location Map_73318 — M6 Rugby
Receptor Location Map_73424 — M5 Sandwell
Receptor Location Map_73773 — M56 Stockport
Receptor Location Map_73920 B — M5 Sandwell
Receptor Location Map_73998 — M4 Wiltshire
Receptor Location Map_74456 — A38 Derby
Receptor Location Map_74590 — M60 Manchester
Receptor Location Map_74768 — M32 Bristol
Receptor Location Map_75235 B — A5103 Manchester
Receptor Location Map_75258 — M27 Southampton
Receptor Location Map_75259 — M27 Southampton
Receptor Location Map_75290 — A59 Sefton
Receptor Location Map_75422 — A50 Stoke-on-Trent
Receptor Location Map_77007 — M60 Manchester
Receptor Location Map_77419 — A45 Northampton
Receptor Location Map_77436 — A34 Oxford
Receptor Location Map_77484 — A50 Stafford
Receptor Location Map_80427 — A1 Gateshead
Receptor Location Map_80428 D — A1 Gateshead
Receptor Location Map_80846 — A282 Thurrock
Receptor Location Map_81006 — A19 Durham
Receptor Location Map_81007 — A19 Durham
Receptor Location Map_81008 — A19 Durham
Receptor Location Map_81178 — A66 Stockton-on-Tees
Receptor Location Map_81374 D — A38 Plymouth
Receptor Location Map_81388 B — M621 Leeds
Receptor Location Map_8147 — A500 Stoke-on-Trent
Receptor Location Map_8340 D — A500 Stoke-on-Trent
Receptor Location Map_8348 C — M621 Leeds
Receptor Location Map_99329 D — A50 Stoke-on-Trent
Receptor Location Map_99331 E — A50 Stoke-on-Trent
Receptor Location Map_99332 A — A50 Stoke-on-Trent
Receptor Location Map_99333 C — A50 Stoke-on-Trent
Receptor Location Map_99335 — A50 Stoke-on-Trent
Receptor Location Map_99337 — A50 Stoke-on-Trent
Receptor Location Map_99614 — M60 Manchester
Receptor Location Map_99631 B — A27 Portsmouth

Audit Summary Report — 16050 — M602 Salford
Audit Summary Report — 16237 — A3 East Hampshire
Audit Summary Report — 17736 — A3 Guildford
Audit Summary Report — 17961 — A19 Stockton-on-Tees
Audit Summary Report — 18061 — A38 Plymouth
Audit Summary Report — 26012 — M4 Hounslow
Audit Summary Report — 26017 — M5 Dudley
Audit Summary Report — 26051 — M61 Bolton
Audit Summary Report — 26064 — M606 Kirklees
Audit Summary Report — 27711 — A4123 West Midlands
Audit Summary Report — 27932 — A63 Hull
Audit Summary Report — 28015 — M602 Manchester
Audit Summary Report — 28018 — M27 Southampton
Audit Summary Report — 28076 — A316 Spelthorne
Audit Summary Report — 28361 — A63 Hull
Audit Summary Report — 28445 — A56 Haslingden
Audit Summary Report — 28772 — A1 Newcastle upon Tyne
Audit Summary Report — 28776 — A1 Gateshead
Audit Summary Report — 36007 — M1 Rotherham
Audit Summary Report — 36063 — M52 Cheshire West and Chester
Audit Summary Report — 36296 — A27 Havant
Audit Summary Report — 38230 — A500 Stoke-on-Trent
Audit Summary Report — 46015 — M5 West Midlands
Audit Summary Report — 46062 — A1(M) Durham
Audit Summary Report — 47243 — A500 Newcastle-under-Lyme
Audit Summary Report — 47892 — M4 Hounslow
Audit Summary Report — 48331 — A63 Hull
Audit Summary Report — 48707 — A1 Newcastle upon Tyne
Audit Summary Report — 56007 — M621 Leeds
Audit Summary Report — 56009 — M621 Leeds
Audit Summary Report — 56033 — M32 Bristol
Audit Summary Report — 56062 — M53 Cheshire West and Chester
Audit Summary Report — 56063 — M621 Leeds
Audit Summary Report — 57767 — A38 Derby
Audit Summary Report — 57783 — A500 Stoke-on-Trent
Audit Summary Report — 57832 — A63 Hull
Audit Summary Report — 6013 — M4 Hillingdon
Audit Summary Report — 6046 — M56 Manchester
Audit Summary Report — 70007 — A66 Stockton-on-Tees
Audit Summary Report — 70206 — M11 Redbridge
Audit Summary Report — 70230 — M6 Birmingham
Audit Summary Report — 70271 — M56 Manchester
Audit Summary Report — 73318 — M6 Rugby
Audit Summary Report — 73424 — M5 Sandwell
Audit Summary Report — 73773 — M56 Stockport
Audit Summary Report — 73920 — M5 Sandwell
Audit Summary Report — 73998 — M4 Wiltshire
Audit Summary Report — 74456 — A38 Derby
Audit Summary Report — 74590 — M60 Manchester
Audit Summary Report — 74768 — M32 Bristol
Audit Summary Report — 75235 — A5103 Manchester
Audit Summary Report — 75258 — M27 Southampton
Audit Summary Report — 75259 — M27 Southampton
Audit Summary Report — 75290 — A59 Sefton
Audit Summary Report — 75422 — A50 Stoke-on-Trent
Audit Summary Report — 77007 — M60 Manchester
Audit Summary Report — 77419 — A45 Northampton
Audit Summary Report — 77436 — A34 Oxford
Audit Summary Report — 77484 — A50 Stafford
Audit Summary Report — 80427 — A1 Gateshead
Audit Summary Report — 80428 — A1 Gateshead
Audit Summary Report — 80846 — A282 Thurrock
Audit Summary Report — 81006 — A19 Durham
Audit Summary Report — 81007 — A19 Durham
Audit Summary Report — 81008 — A19 Durham
Audit Summary Report — 81178 — A66 Stockton-on-Tees
Audit Summary Report — 81374 — A38 Plymouth
Audit Summary Report — 81388 — M621 Leeds
Audit Summary Report — 8147 — A500 Stoke-on-Trent
Audit Summary Report — 8340 — A500 Stoke-on-Trent
Audit Summary Report — 8348 — M621 Leeds
Audit Summary Report — 99329 — A50 Stoke-on-Trent
Audit Summary Report — 99331 — A50 Stoke-on-Trent
Audit Summary Report — 99332 — A50 Stoke-on-Trent
Audit Summary Report — 99333 — A50 Stoke-on-Trent
Audit Summary Report — 99335 — A50 Stoke-on-Trent
Audit Summary Report — 99337 — A50 Stoke-on-Trent
Audit Summary Report — 99614 — M60 Manchester
Audit Summary Report — 99631 — A27 Portsmouth

Commission 2

Commission 3

PCM Link Evaluation Strategy

Following the agreement with the Joint Air Quality Unit (JAQU), a number of links have been identified as above the permissible levels.

We have developed an evaluation strategy to:

  • understand and report when each link is compliant
  • determine whether any mitigation is delivering the improvements
  • confirm when any mitigation can be removed whilst ensuring the section of the SRN remains compliant

Evaluation approach

Air quality monitoring to be deployed for all links confirmed as non-compliant and assessed within 10% of the limit value, i.e. (36-40µg/m³).

Monitoring to be deployed to at least one site as a minimum, but ideally three, alongside the SRN representative of qualifying feature(s).

Monitoring will continue for at least two years after the respective section of the SRN is modelled to come into compliance.

Monitored concentrations will be evaluated at 6 month intervals, (allowing 2 months for tube analysis by the labs):

  • mid-year review - end Aug year – covering first 6 months
  • annual review and report - end Feb year – calendar year annual average

Removing mitigation will be recommended when concentrations are reported below 36µg/m³.

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