travel expenses
Subject to and in accordance with regulations promulgated by the Committee on Rules and Administration of the Senate, a Senator and the employees in his office shall be reimbursed under this section for travel expenses incurred by the Senator or employee while traveling on official business within the United States. The term “travel expenses” includes actual transportation expenses, essential travel-related expenses, and, where applicable, per diem expenses (but not in excess of actual expenses). A Senator or an employee of the Senator shall not be reimbursed for any travel expenses (other than actual transportation expenses) for any travel occurring during the sixty days immediately before the date of any primary or general election (whether regular, special, or runoff) in which the Senator is a candidate for public office (within the meaning of section 30101(b) of title 52), unless his candidacy in such election is uncontested. For purposes of this subsection and subsection (a)(6) of this section, an employee in the Office of the President pro tempore, Deputy President pro tempore, Majority Leader, Minority Leader, Majority Whip, Minority Whip, Secretary of the Conference of the Majority, or Secretary of the Conference of the Minority shall be considered to be an employee in the office of the Senator holding such office.