All contracts, deeds, bonds or agreements entered into or made by the former roads authority for a road which becomes a trunk road, being contracts, deeds, bonds or agreements subsisting on the day on which it so becomes, shall, in so far as they relate to property and liabilities transferred to the Secretary of State in respect of that road, have effect with the substitution of the Secretary of State for the authority and may be enforced by or against the Secretary of State accordingly.