Under regulations prescribed under
section 5738 of this title, an employee who transfers between points inside the continental United States, instead of being paid for the actual expenses of transporting, packing, crating, temporarily storing, draying, and unpacking of household goods and personal effects, shall be reimbursed on a commuted basis at the rates per 100 pounds that are fixed by zones in the regulations. The reimbursement may not exceed the amount which would be allowable for the authorized weight allowance. However, under regulations prescribed under
section 5738 of this title, payment of actual expenses may be made when the head of the agency determines that payment of actual expenses is more economical to the Government.