Before any such ¹ special license to unlade shall be granted, the master, owner, or agent of such ¹ vessel or vehicle, or the person in charge of such ¹ vehicle, shall be required to deposit sufficient money to pay, or to give a bond in an amount to be fixed by the Secretary conditioned to pay, the compensation and expenses of the customs officers and employees assigned to duty in connection with such ¹ unlading at night or on Sunday or a holiday, in accordance with the provisions of section 267 of this title. In lieu of such deposit or bond the owner or agent of any vessel or vehicle or line of vessels or vehicles may execute a bond in an amount to be fixed by the Secretary of the Treasury to cover and include the issuance of special licenses for the unlading of such vessels or vehicles for a period not to exceed one year. Upon a request made by the owner, master, or person in charge of a vessel or vehicle, or by or on behalf of a common carrier or by or on behalf of the owner or consignee of any merchandise or baggage, for overtime services of customs officers or employees at night or on a Sunday or holiday, the appropriate customs officer shall assign sufficient customs officers or employees if available to perform any such services which may lawfully be performed by them during regular hours of business, but only if the person requesting such services deposits sufficient money to pay, or gives a bond in an amount to be fixed by the ² such customs officer, conditioned to pay the compensation and expenses of such customs officers and employees, who shall be entitled to rates of compensation fixed on the same basis and payable in the same manner and upon the same terms and conditions as in the case of customs officers and employees assigned to duty in connection with lading or unlading at night or on Sunday or a holiday. Nothing in this section shall be construed to impair the existing authority of the Treasury Department to assign customs officers or employees to regular tours of duty at nights or on Sundays or holidays when such assignments are in the public interest: Provided, That the provisions of this section, sections 1450 and 1452 of this title, and the provisions of section 267 of this title insofar as such section 267 of this title requires payment of compensation by the master, owner, agent, or consignee of a vessel or conveyance, shall not apply to the owner, operator, or agent of a highway vehicle, bridge, tunnel, or ferry, between the United States and Canada or between the United States and Mexico, nor to the lading or unlading of merchandise, baggage, or persons arriving in or departing from the United States by motor vehicle, trolley car, on foot, or by other means of highway travel upon, over, or through any highway, bridge, tunnel, or ferry. At ports of entry and customs stations where any merchandise, baggage, or persons shall arrive in or depart from the United States by motor vehicle, trolley car, on foot, or by other means of highway travel upon, over, or through any highway, bridge, tunnel, or ferry, between the United States and Canada or between the United States and Mexico, the appropriate customs officer, under such regulations as the Secretary of the Treasury may prescribe, shall assign customs officers and employees to duty at such times during the twenty-four hours of each day, including Sundays and holidays, as the Secretary of the Treasury in his discretion may determine to be necessary to facilitate the inspection and passage of such merchandise, baggage, or persons. Officers and employees assigned to such duty at night or on Sunday or a holiday shall be paid compensation in accordance with existing law as interpreted by the United States Supreme Court in the case of the United States v. Howard C. Myers (320 U.S. 561); but all compensation payable to such customs officers and employees shall be paid by the United States without requiring any license, bond, obligation, financial undertaking, or payment in connection therewith on the part of any owner, operator, or agent of any such highway vehicle, bridge, tunnel, or ferry, or other person. As used in this section, the term "ferry" shall mean a passenger service operated with the use of vessels which arrive in the United States on regular schedules at intervals of at least once each hour during any period in which customs service is to be furnished without reimbursement as above provided.