(a) No local authority shall alter, amend, annul, or abrogate any posted speed regulation on any facility of the state highway system, but may, in regard to facilities traversing their respective jurisdictions, petition the State Highway Commission in a hearing to present argument on such potential action.
(b) This section is supplemental to existing law and shall in no way derogate the duty of local courts, local peace officers, and the Department of Arkansas State Police to enforce posted traffic and speed regulations within their jurisdictions.