Motorway 'pollution tunnels' capable of capturing toxic fumes could be introduced by Highways England under plans to improve the nation's air quality.
The national road operator has already trialled different barriers capable of absorbing pollution, with a potential roll out of tent-like canopies being considered.
A trial featuring wood panels four metres and six metres high has taken place on the M62 near junction 18 in Manchester and a second ongoing trial features a three metre high fence coated in a mineral polymer material capable of absorbing nitrogen dioxide.
Highways England chief executive Jim O'Sullivan
In its first major intervention into the air quality debate, which so far has focused on councils, Highways England has released an air quality strategy setting out how it will use £100m in the current Road Investment Strategy to improve air quality on and around the strategic road network (SRN).
It states: ‘We are also investigating if we can reduce the costs to construct a canopy, which is a tunnel-like structure designed to prevent vehicle emissions reaching our neighbours, to make this a viable solution.’
The idea was swiftly criticised by the RAC, whose roads policy spokesman, Nick Lyes, said: ‘We question whether constructing tunnel-like canopies, even if they are made from a material that can partially clean the air, is the right way to deal with the problem. All this will do is concentrate potentially toxic air over the road which will have an impact on those inside their vehicles who breathe in the trapped pollution.
‘The solution should be about reducing levels of pollution by accelerating the transition to ultra-low and zero emission vehicles and encouraging better traffic flow through variable speed limits – something Highways England has started doing on smart motorways.’
Highways England's chief executive Jim O’Sullivan and chairman Colin Matthews write: ‘We are keen for partners to help us solve these air quality challenges and work with us as we implement the solutions.'
The strategy states that Highways England will work with operators to ensure that rapid charging points at motorway service areas become a comprehensive national network and ‘are already working to ensure that 95% of our network will have a charging point every 20 miles’.
It adds that rapid charging points, which can charge a ULEV in less than 30 minutes, will be used ‘wherever possible’.
Following the publication last month of the Government’s national air quality plan, which banned new petrol and diesel cars after 2040, the strategy states: ‘We will support local authorities as they explore options for their local air quality plans.’
In a move that could impact the highways asset itself, Highways England said information from continuous monitoring stations will help ensure that when schemes are planned and developed 'we are able to plan for and take account of air quality at an earlier stage, ensuring that we deploy the most suitable design and mitigation if required'.