All roads in the state road system shall be classified by the state road commissioner. Classification shall be according to functional level of service, either as expressway, trunkline, feeder, or state local service. The designation of a road as expressway, trunkline, feeder, or state local service, shall be subject to change, however, whenever in the judgment of the commissioner altered conditions require that a road be reclassified from one category to another.
W. Va. Code § 17-4-3