Okla. Stat. tit. 47, § 47-15-101: Provisions uniform throughout state

The provisions of Chapters 10, 11, 12, 13 and 14 of this act

shall be applicable and uniform throughout this state and in all

political subdivisions and municipalities therein and no local

authority shall enact or enforce any ordinance, rule or regulation

in conflict with the provisions of such chapters unless expressly

authorized herein. Local authorities may, however, adopt additional

traffic regulations which are not in conflict with the provisions of

such chapters.