Reimbursement for Ground Transportation at Destination
Travel to and from airport and downtown areas should be confined to regularly scheduled transportation service whenever such service is less costly than taxicabs. Necessary taxicab charges including reasonable gratuities are permitted if public transportation is not readily available or cost effective. For expenses in excess of $10.00, original receipts plus justification of travel means are required for reimbursement.
See Airport/Parking reimbursement rates http://www.tcnj.edu/~budfin/travel/Parking.html