(a) The Oklahoma Department of Highways or other designated authorities are hereby authorized to determine those portions of any highway where overtaking and passing or driving to the left of the roadway would be especially hazardous and may by appropriate signs or markings on the roadway indicate the beginning and end of such zones and when such signs or markings are in place and clearly visible to an ordinarily observant person every driver of a vehicle shall obey the directions thereof.
(b) Where signs or markings are in place to define a no-passing zone as set forth in paragraph (a) no driver shall at any time drive to the left side of the roadway within such no-passing zone or on the left side of any pavement striping designed to mark such no-passing zone throughout its length.
Laws 1961, p. 377, § 11-307.