As used in this part, the term "contract" means a contract or subcontract entered into by a municipality with any person, the state or federal government or an agency of either, with another municipality or municipalities, with a county or counties, or with any combination of any of the foregoing entities, for the construction, reconstruction, or maintenance of all or part of a public road in said municipality, including but not limited to a contract or subcontract for the purchase of materials, for the hiring of labor, for professional services, or for other things or services incident to such work.