Provisions of this article shall not apply to authorized emergency vehicles or to vehicles or machinery used in the construction or maintenance of highways, and such vehicles or machinery may be operated on any part of the road, whether same is open to traffic or closed, when such operation is necessary in the maintenance or construction of said highway; provided, that the Department of Highways shall protect all such operations with adequate warnings, signs, signals, lights, devices, or flagmen. Laws 1961, p. 388, § 11-1005.
Oklahoma Legal Code