You asked
Please can you provide the relevant documents that show which council is responsible for the maintenance of a particular highway.
We said
Thank you for your request. The requested information is not held by the Office for National Statistics. We feel that questions regarding geographic locations would be best answered by Ordnance Survey. I have attached some links to their website that may be of use.
https://www.ordnancesurvey.co.uk/business-and-government/products/boundary-line.html