The department shall provide a system of maintenance for all state highways to which section 1001 may apply and for all state aid highways to which section 802 may apply so that all sections of such highways may be effectually and economically preserved and maintained, in accordance with the best maintenance practice insofar as funds will permit. This section does not include snow removal work on state aid highways or town ways. [PL 1981, c. 698, §99 (AMD).]