Air quality

What we are doing

We’re implementing a programme of measures around the country to improve air quality at specific locations on the Strategic Road Network. These locations are called Pollution Climate Mapping (PCM) links.

These measures include:

  • traffic management
  • managing speeds to reduce emissions
  • working to accelerate the uptake of zero emission vans
  • air quality barriers

Traffic management

Traffic management includes activites such as diversions, speed control, signal timing/location, signage/dynamic signage, junction reconfiguration or changes to road alignment. All these can help manage local air quality issues.

To improve air quality at non-compliant locations on the strategic road network, we’ve been assessing the potential impact of traffic management measures at these sites. In some cases we believe traffic management could potentially improve the air quality, so we’re now undertaking further work to develop plans for these sites. Options being considered include:

  • junction improvements, closing junctions or particularly on and off slip roads
  • changing the timing of traffic lights and Installing new traffic lights on roundabouts
  • exploring routing HGVs
  • introducing dynamic signs that advises drivers according to the traffic volumes
  • reviewing the speed limits and installing addition speed cameras
  • working with local authorities to improve bus and cycle lane improvements to reduce local traffic

Managing speeds to reduce emissions

We have been investigating the effects of different speeds and driving styles on vehicle emissions. We’re now looking at a number of locations to introduce reduced speeds over short sections, which will add only a few seconds to the average journey times. We believe this is the right thing to do to protect public health.

The speed limits will be clearly displayed through roadside signs. The choice of sign type will depend on how long the speed limit is expected to be in force.

Experience from Wales

We have been following closely the work to reduce speed limits to 50mph in Wales. Emissions of nitrogen dioxide have reduced at all five locations on the motorway and trunk road network where 50 mph speed limits were introduced, monitored data shows. While air quality remains a complicated issue and further evidence is needed to prove the speed limits have had an impact on NO2 limits, the initial findings show positive improvement in air quality after the first full year of the speed limits being introduced.

Working to accelerate the uptake of zero emission vans

The use of vans on our network has grown significantly over the last few years and is forecast to grow further. These vehicles produce a disproportionate amount of pollutants – 33% of the oxide of nitrogen (NOX) emissions from 15% of road traffic. Importantly zero emission alternatives are available and absolutely viable for many.

We’ve been working with Leeds City Council to implement a try-before-you-buy scheme in an effort to accelerate the uptake of electric vans. Our research with the Energy Saving Trust showed that providing vans users with the opportunity to try a vehicle for free for up to two months will give many confidence to make the switch and buy their own electric vans.

Case study: Leeds Electric Van centre of Excellence

We’ve provided almost £2 million of funding for a fleet of up to 70 electric vans to be purchased for demonstrations This is a complementary measure to the Leeds Clean Air Zone and will help contribute to cleaner air on our M621.

If you’re a business based in West Yorkshire, see if you might qualify for a free trial of an electric van for up to two months for free.

By the end of March 2020 we contracted with Coventry City Council, Kent County Council, Nottingham City Council and Sheffield City Council to deliver a similar ‘try before you buy’ electric van scheme to the Leeds one. We’re also actively engaged with a number of other authorities, especially where we need to work hard to deliver cleaner air, to see if they can collaborate to deliver more schemes elsewhere.

Air quality barriers

We’re currently exploring the opportunities for physical barriers to improve air quality at specific locations on our road network.

These provide a physical barrier to divert pollution away from homes and sensitive locations. Our pollution monitoring in Holland close to an existing tall sound barrier, installed to reduce noise, has produced interesting results. These findings suggest this type of barriers could help improve air quality, and we are actively undertaking technical development work to assess how and where these types of barriers could bring benefits at hotspots on our road network.

Improving air quality on our network

Find out more about our approach to improving air quality.

Get in touch

If you have something you would like to discuss with us, please get in touch by emailing