Neb. Rev. Stat. §§ 81-1014
No agency shall allow mileage reimbursement charges on travel expense vouchers of state officers or employees unless there is filed with the expense voucher a statement signed by the director of the agency or his or her authorized representative declaring that the use of a privately owned vehicle was authorized according to the provisions of section 81-1176. State officers or employees may be authorized to use their personal automobiles on state business at the convenience of the agency, or at the convenience of the state officer or employee, as previously agreed upon by the officer or employee and the agency involved, and shall receive a mileage reimbursement for each mile actually and necessarily traveled in each calendar month as provided in section 81-1176.
Neb. Rev. Stat. §§ 81-1014