Highways England is looking at whether microplastics are washed off roads and into the environment.

The government-run organisation in charge of England’s motorways has launched a study into microplastics washed off the country’s road network. Highways England is looking into the environmental impacts of surface water that runs off roads, with emphasis on how that affects the level of microplastics in the environment.

In essence, the research will assess whether there is a “microplastic waste issue” from the water that runs off roads in wet weather. It’s hoped the organisation will be able to use the research to better understand the issue, then identify further studies that could shed light on ways to address the problem.

Microplastics are often found on roads as tyres, brakes and road markings degrade during normal use. As these items gradually wear away, small particles are left on the road surface, where they may be washed away into the ground surrounding the roadside.

Aerial view of the M56 motorway in the Cheshire countryside

This new study has been kick-started by initial research identifying the evidence that exists and looking into what further research should be undertaken. Academic “desk top” findings have also secured funding so the issue can be more closely investigated with “on-road” investigations.

Although Highways England says it already has “clear assessment and design standards” for maintaining and improving drainage systems on its network, it hopes the studies will guide improvements in future. The organisation says it is committed to “minimising the environmental impact of its network and in particular the vehicles using it”.

M25 London Orbital Motorway near Junction 18 in Hertfordshire UK

Alice Horton, from the National Oceanography Centre, said the research could help limit the impact of roads on the environment.

“This research is a key step in understanding the contribution of the strategic road network to microplastic pollution within the terrestrial and aquatic environment,” she said. “This study has identified the critical knowledge gaps that should be addressed going forwards to enable us to understand the extent and implications of microplastic runoff from roads, and measures that should be put in place to limit this environmental contamination.

Meanwhile Michael Whitehead, principal advisor for water at Highways England, said the research would help the organisation’s “future decision making”, including potential measures to limit microplastic pollution.

“Highways England takes environmental issues seriously and recognises the global concern around microplastic pollution,” he said. “We have undertaken this research together with the Environment Agency and other industry experts to better understand the potential contribution that road transport has on microplastics. The outcome of further research will be the evidence base to inform future decision making, enabling us to take positive action to manage identified risks, inform policy and identify further areas of research.

Traffic on the M4 motorway near junction 28 Newport & Cardiff