(a) The secretary of administration may fix rates of mileage allowance for travel by privately owned conveyances for official purposes and the rates so fixed may be paid to public officials, except as otherwise specifically provided by law. The secretary may fix a different rate of mileage allowance for each of the following privately owned conveyances:

(1) Automobiles;

(2) motorcycles;

(3) aircraft;

(4) vehicles specially equipped for the physically disabled; and

(5) other privately owned conveyances.

(b) Each rate of mileage allowance fixed by the secretary shall be fixed only after consideration of actual costs incurred in using privately owned conveyances, the rates allowed by the internal revenue service, increased costs due to any energy crisis and the general inflationary situation, and such other matters as the secretary deems pertinent.

(c) The rates of mileage allowance authorized by this section may be revised as conditions require but shall not exceed the lowest of the following rates:

(1) The rate allowed by the internal revenue service;

(2) the rate used in preparing the governor’s budget report under Kan. Stat. Ann. § 75-3721, and amendments thereto; or

(3) any revision of the rate described in paragraph (2) as specifically directed in appropriation acts of the legislature.

(d) Each rate of mileage allowance fixed by the secretary under this section shall be the rate of mileage allowance for official travel by the applicable privately owned conveyance until a different rate is fixed therefor by the secretary under this section.