The deeds will set out who owns what freeholds and who has leaseholds and from whom. Assuming the driveway is not 'adopted' - i.e. maintainable at public expense then each business lease is highly likely to contain easements (rights of way) across your drive (assuming the drive is actually part of your freehold and therefore 'owned' by you). The rents those business pay will be set out in their leases (including maintenance charges). A landlord won't be able to make additional charges unless the signed leases allow this. You should also be able to see these rights of way set out in your deeds.