A reference route is an unsigned highway assigned by the New York State Department of Transportation (NYSDOT) to roads that possess a signed name (mainly parkways), that NYSDOT has determined are too minor to have a signed touring route number, or are former touring routes that are still state-maintained. The majority of reference routes are owned by the state of New York and maintained by NYSDOT; however, some exceptions exist. The reference route designations are normally posted on reference markers, small green signs located every tenth-mile on the side of the road, though a few exceptions exist to this practice as well.