(a) Route 170 is from: (1) Los Angeles International Airport to Route 90. (2) Route 2 to Route 101 in Los Angeles. (3) Route 101 near Riverside Drive to Route 5 near Tujunga Wash. (b) (1) Notwithstanding subdivision (a), the commission may relinquish to the City of Los Angeles the portion of Route 170 that is described in paragraph (2) of subdivision (a), pursuant to the terms of a cooperative agreement between the city and the department, upon a determination by the commission that the relinquishment is in the best interests of the state. (2) A relinquishment under this subdivision shall become effective immediately following the recordation by the county recorder of the relinquishment resolution containing the commission`s approval of the terms and conditions of the relinquishment. (3) On and after the effective date of the relinquishment, both of the following shall apply: (A) The portion of Route 170 relinquished under this subdivision shall cease to be a state highway. (B) The portion of Route 170 relinquished under this subdivision may not be considered for future adoption under Section 81.