Your agency may authorize the shipment of UAB by expedited means when:

(a) Shipment by a lower cost mode cannot deliver the items being shipped by the time they will be needed by the employee and/or the employee's immediate family; or

(b) You certify that expedited shipment of your UAB is necessary to carry out your assigned duties; or

(c) Your agency determines that an expedited shipment is necessary to prevent undue hardship to you and members of your immediate family.