Okla. Stat. tit. 74, § 74-500.4

A. Authorized persons traveling on official state business

within the State of Oklahoma may utilize railroads, airplanes,

buses, whether intracity or intercity, or other public conveyance.

Reimbursement for fares paid for airplane transportation shall not

exceed coach class fare except as provided herein. Reimbursement

for fares paid for airplane transportation may be at the business

class fare rate for international travel. Other public conveyance

fares shall not exceed the lesser of the normal charge or coach

class airplane fare. Taxicab or rideshare fares within the State of

Oklahoma and communication charges may be reimbursed only upon

justification as to the necessity for their use.

B. Agency heads or their authorized designees may approve the

use of motor vehicles for official travel within the State of

Oklahoma. If available, agency owned motor vehicles or motor

vehicles leased from the State Motor Pool, either on a full-time

basis or for individual trips, shall be utilized for such travel.

Reimbursement for use of privately owned motor vehicles may be

authorized by the agency head.

C. Reimbursement for authorized use of privately owned motor

vehicles shall not exceed the amount prescribed by the Internal

Revenue Code of 1986, as amended, or rules, procedures or other

action by the Internal Revenue Service, for use in determining the

standard mileage rate allowed for a business expense deduction.

Distances for which reimbursement for use of privately owned motor

vehicles is claimed shall be actual business miles based on a

recognized Global Positioning System (GPS) or based on map and

vicinity business mileage.