To ask the Secretary of State for Transport, what steps he is taking to help prevent the growth of invasive Japanese knotweed alongside highways.

National Highways has a legal responsibility to prevent Japanese knotweed from spreading to adjoining land where it is on the Strategic Road Network (SRN) and where National Highways is the landowner.

National Highways works on the principle that once a location has been identified and the extent of the infestation established, an appropriate method of control is then enacted to ensure eradication and to prevent re-infestation. Where Japanese knotweed is identified on adjacent land, National Highways will work with landowners to ensure eradication and prevention. National Highways, its service providers and supply chain, follow the Department of Environment, Food and Rural Affairs (DEFRA) and Environment Agency guidance.

On the local network, local highway authorities have a duty under Section 41 of the Highways Act 1980 to maintain the highways network in their area, this includes issues such as overgrown vegetation. The Act does not set out specific standards of maintenance, as it is for each individual local highway authority to assess which parts of its network need repair and what standards should be applied, based upon their local knowledge and circumstances.