Question to the Department for Transport:

To ask the Secretary of State for Transport, if he will make an assessment of the (a) prevalence of Japanese knotweed on (i) railway embankments and (ii) other railway land and (b) potential impact of such Japanese knotweed on nearby (A) homes and (B) businesses.

Routine vegetation inspections are carried out by Network Rail on the full rail lineside estate on a three to four year cycle. Any Japanese knotweed identified on the estate is recorded, including details of how far the knotweed is from the railway tracks and from the boundary fence onto neighbouring land. For recording purposes, the lineside estate is broken down into eighth of mile sections. Records are currently held on file for 87,000 sections of lineside estate, knotweed was present in 1.12% of those sections when last inspected.

Network Rail has an established regime to deal with Japanese knotweed on the lineside estate, whether identified by a Network Rail inspection or reported by a neighbour or member of the public. Network Rail colleagues use the recorded information in line with its specific knotweed management guidance to prioritise locations for treatment and set up chemical treatment programmes that will run for three to five years or until the problem is controlled. Where knotweed is found on both sides of a boundary fence, processes are in place to enable Network Rail to work in collaboration with the neighbouring landowner to set up the most effective treatment for that location.