[Code of Federal Regulations] [Title 41, Volume 4] [Revised as of July 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 41CFR301-2.5] [Page 24] TITLE 41--PUBLIC CONTRACTS AND PROPERTY MANAGEMENT CHAPTER 301--TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES PART 301-2_GENERAL RULES--Table of Contents Sec. 301-2.5 What travel arrangements require specific authorization or prior approval? You must have a specific authorization or prior approval for: (a) Use of premium-class service on common carrier transportation; (b) Use of a foreign air carrier; (c) Use of reduced fares for group or charter arrangements; (d) Use of cash to pay for common carrier transportation; (e) Use of extra-fare train service; (f) Travel by ship; (g) Use of a rental car; (h) Use of a Government aircraft; (i) Payment of a reduced per diem rate; (j) Payment of actual expense; (k) Travel expenses related to emergency travel; (l) Transportation expenses related to threatened law enforcement/ investigative employees and members of their families; (m) Travel expenses related to travel to a foreign area; (n) Acceptance of payment from a non-Federal source for travel expenses, see chapter 304 of this subtitle; and (o) Travel expenses related to attendance at a conference. Note to Sec. 301-2.5: Paragraphs (c), (i), (n), and (o) of this section require a written or electronic advance authorization. [[Page 25]]