(a) As used in this subchapter, unless the context otherwise requires, “functional classification” means the grouping of public ways by likeness of service or purpose into classes or systems according to the character of service they are intended to provide. The frame of reference is the sense of service offered to and expected by the road user. Neither ownership nor administrative responsibility is relevant in grouping by function.
(b) All definitions of terms adopted for the 1972 National Transportation Needs Study are incorporated by reference in this subchapter. The term “functional classification”, defined herein, is in accordance with the definition contained in the study reports.