Road Sign cleaners - Find a freedom of information request

I would like to know if is there any companies that clean regularly the road signs?

Sign cleaning is carried out on our behalf by our Highway Works Maintenance Term Contractor, Balfour Beatty, under a long-term contract.

We have a policy to clean signs on the MRN, Hierarchy 1 and Hierarchy 2 carriageway network once a year. For other hierarchies, road signs are cleaned where issues are identified by our local highway’s teams.

There is obviously a focus on those with an implication for safety of the public but given the budgetary pressure on the highways service, other issues may be given priority.