7 January 2021
The RSMA has today welcomed the announcement that Highways England (HE) plans to conduct field sampling of road water runoff from the SRN and quantify unambiguously the content of microplastic pollution therein. The planned HE ‘on road’ investigation which will collect and analyse samples of road water runoff to establish the ‘presence or absence of microplastics’ will provide HE ‘the evidence base to inform future decision making’ and allow it to manage identified risks, inform policy and identify further areas of research.
The RSMA highlights the paucity of empirical evidence in the majority of research that has to date been conducted in this area and has been concerned for some time that much of the work published does not reflect the UK environment. The majority has been conducted overseas on road networks where differences in pavement and road marking products, weather and vehicle interfaces (tyre studs, chains and ploughs) provide a very different research perspective to that which exists within the UK. Such studies have an over reliance on modelled information and have, in some cases, been shown to be based on ill-founded assumptions which lack scientific rigour; the veracity of which is now widely questioned.
Stu McInroy, CEO RSMA said, “The RSMA welcomes the HE initiative to undertake robust research to inform policy discussions. The HE empirical study based on real world sampling/data from the SRN should be granular enough to quantify once and for all, without question or ambiguity, the level of thermoplastic road marking residue found to be present in water runoff from the strategic road network. We should also remain mindful that the term ‘thermoplastic’ is something of a misnomer. Thermoplastic road marking materials are referred to in this way because they have ‘plastic-like’ characteristics; in the significant majority of thermoplastic road marking products only 1.0% of the material is actually plastic.
“I am however concerned that HE intends to evaluate new road marking materials as part of the runoff study whilst at the same time acknowledging that no figures, backed up by empirical research, exist at this point in time; this appears to prejudge without evidence that thermoplastic road markings are a significant generator of pollutants and perhaps the HE focus should be elsewhere.
“The RSMA would welcome the opportunity to contribute to the discussion and provide subject matter expertise to support the HE research, and of course continued HE support for the RSMA road trial planned for July 2022 would provide a perfect platform for the industry to test new, innovative, sustainable and increasingly environmentally friendly products, as without such a trial there is no route by which the products can reach the road.
“I am confident that the HE research will prove unequivocally that thermoplastic road markings generate a minute amount of microplastic pollutants when compared with tyre, brake and road surface detritus.”