(a) A state employee is entitled to be reimbursed as provided by this subchapter for the employee’s use of a personally owned or leased motor vehicle.
(b) A state employee may not be reimbursed under this subchapter for an expense other than mileage, tolls, and parking.

(c) A state employee may not be reimbursed for mileage incurred in traveling between the employee’s residence and place of employment in a personally owned or leased motor vehicle unless the travel:
(1) is necessitated by extraordinary circumstances; and
(2) occurs outside the hours the employee is working.