Air quality - Highways England's programme of activity

Date: Thursday 22 July 2021

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Highways England is 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 activities 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, Highways England has 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 they are 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
Highways England has a legal duty to tackle air quality around our network and are committed to meeting the targets in the Government's Nitrogen Dioxide (NO2) plan.

Ultimately the air quality challenge will be solved ‘at the tailpipe’ by vehicle manufacturers and changes in vehicle use.

Until this happens they will continue an extensive programme of pioneering research and solutions. As part of this, they are introducing 60 mph speed limits on short sections of their network, each up to 4.5 miles, where action needs to be taken. This will be on a trial basis, and the temporary reduced speed limits will stay in place until the shift to cleaner vehicles means they can remove the restrictions and maintain clean air.

They expect there will be a reduction in NO2 when traffic speed is reduced from 70 to 60mph in these locations, based on extensive traffic and air quality modelling, air quality monitoring and wider research programme.

The speed limits will be clearly displayed through roadside signs and variable messages signs.

Learn more about the air quality speed limit trials.

 

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