(1) ORS 371.605 to 371.660 do not apply to any state highway.
(2) The county governing body may designate any public road improved under ORS 371.605 to 371.660 as a county road without invalidating the assessments levied for the purpose of the improvements.
(3) Except as otherwise provided in this section, a county may supersede any provision in ORS 371.605 to 371.660 by enacting an ordinance under ORS 203.030 to 203.065 authorizing the use of assessments to finance local improvements, as defined in ORS 223.001, and providing a procedure for levying such assessments.