Lower speed limits and vehicle diversions are being imposed on some of the country’s busiest roads under plans to cut illegally high levels of air pollution.
Highways England has identified 30 short stretches of motorways and A-roads where levels of toxic nitrogen dioxide (NO2) emissions consistently breach legal limits. An additional 35 areas are being further investigated.
A report published today showed that the stretches of polluted road pass through or near large English towns and cities including Birmingham, Bristol, Derby, Hull, Gateshead, Leeds, London, Oxford, Plymouth and Stoke-on-Trent.
It found that 30 were above annual limits and 36 were below. A further 35 were also below the legal limit although they are being subjected to additional checks to “corroborate outputs of earlier analysis”.
The worst stretch was on the A3 through Guildford where provisional readings in 2020 were at 89 mcg. The A34 west of Oxford had levels of 69 mcg, while it was 64 mcg on the Dartford Crossing east of London, 64 mcg on part of the A38 through Derby and 55 mcg on the A316 near Sunbury-on-Thames, Surrey.
Levels of NO2 on part of the A3 through Guildford in Surrey were more than twice the legal limit of 40 micrograms per cubic metre of air throughout last year, despite a sharp drop in traffic during the pandemic. In at least nine out of the thirty areas identified the speed limit has been or will be cut to 60mph or below to prevent vehicles revving engines and raising emissions levels further.
This includes sections of the M32 in Bristol, the M6 near Birmingham and the M1 between Sheffield and Rotherham. Other interventions could include diverting HGVs away from affected roads at peak times and encouraging the use of electric vans with a “try before you buy” scheme. In Guildford a 9.3-metre barrier is being considered beside the A3 to shield the area from fumes.
Eight out of nine lower speed limits have already been introduced on the road network, while a feasibility study is ongoing into whether another will be introduced on the A38 near Plymouth.
Highways England admitted there were “no viable measures” to cut pollution in more than half of the worst-affected parts of the network. It said that air quality was forecast to drop below illegal levels in five of these areas this year, although the remaining sections could be subjected to high pollution beyond 2021. Further investigations will now be carried out into these stretches.
Highways England, a state-owned company, defended its record, insisting that air quality was within legal limits on the “vast majority” of the 4,300-mile strategic road network. The conclusions, however, angered environmental groups.
NO2 is largely produced by diesel vehicles and irritates the eyes, nose and throat. Prolonged exposure has been linked with breathing problems and premature death. Rebecca Lush, of Transport Action Network, a campaign organisation, said: “It’s not acceptable for Highways England just to give up on over half the identified sites where people are living with intolerable and illegal air pollution.”
In a landmark judgment late last year, a coroner found that air pollution was a factor in the death of Ella Adoo-Kissi-Debrah, nine, who lived near the busy South Circular Road in London. It was the first time in Britain that poor air quality had been listed as a cause of death.
Mike Wilson, the chief highways engineer at Highways England, said: “Air quality is within legal limits across the vast majority of our road network and the picture is improving.
“There are a number of locations where we have so far been unable to identify any measures that provide a viable measure which is available to us to implement. We will work with the local authorities in each area to identify solutions that we can deliver together, and we continue to work with government to explore potential options.”
He said “the long-term answer is to move to cleaner, low and zero emission vehicles”.