studies shall be obliged to perform, in the province or subprovince granting such aid, the duties of th e profession for which they have been prepared, for a period of time equal to that during which they have received their allowance; but this obligation shall not operate to prevent such students from going abroad upon a Government scholarship at the expens e of the Insular Government, upon successfully passing a competitive examination therefor. [2146-5.] Toll Roads, Bridges, and Ferries SECTION  2057 . Provincial Toll Roads, Bridges, and Ferries . — When the provincial board of any province shall deem such course to be necessary for the proper maintenance of any provincial road within the province, it may designate such road, or part thereof,  or any bridge, or ferry built, or to be built, or maintained as a part thereof, as a toll road, bridge, or ferry, and may fix the rates of toll or ferriage to be paid for the use thereof. [1617-1.] No road or highway so designated shall be continued as a toll road or highway for a longer period than five years. [1617-4.] SECTION  2058 . Collection and Application of Tolls . — In the exercise of the authority hereinabove conferred, the provincial board may erect toll gates or equip ferries and may employ the persons necessary to operate the same. The proceeds derived from such  sources shall be applied to the repair and maintenance of the road upon which the collections are made. [1617-2.] SECTION  2059 . Establishment of Toll Ferry Upon Municipal Road by Action of Provincial Board.  — Whenever for thirty days after service of a request by the provincial board, any municipality shall decline or neglect to establish and maintain a suitable ferry  over any stream or other water situated upon the course of a municipal road, the provincial board may establish and maintain a provincial toll ferry at such place, in the manner above provided. [1672-1.] SECTION  2060 . Persons Exempt from Tolls . — No toll or ferriage ARTICLE  X Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 608