Chap. 0482 An Act relative to the care, control and maintenance of certain public highway bridges Be it enacted, etc., as follows: Section 1. On January first, nineteen hundred and forty-nine, the care, control and maintenance of every public highway bridge with a clear span of not less than twenty feet located on a through route, including any former bridge in direct continuation of a state highway, but excluding any bridge under the control of the metropolitan district commission and any bridge referred to in section two of chapter six hundred and ninety of the acts of nineteen hundred and forty-five, are hereby transferred to the department of public works and thereafter such bridge shall be a state highway and the cost of the care, control and maintenance thereof shall be paid out of the highway fund; provided, that prior to January first, nineteen hundred and forty-nine, the public authority in charge of such bridge shall have filed with said department approval of the transfer aforesaid. Until June thirtieth, nineteen hundred and forty-nine, all employees employed in the operation of the draw of any bridge so made a state highway shall continue to be so employed and the cost of the operation of such draw shall be paid by the public authority having charge of the bridge and said authority shall be reimbursed by the commonwealth for the actual cost of the operation thereof from the highway fund. Said department shall file with the clerk of the house of representatives on or before the first Wednesday in January, nineteen hundred and forty-nine, a complete list of the bridges made state highways, as provided in this section. For the purposes hereof, a through route is defined to be any route shown on a map entitled "Route Map of Massachusetts, 1941", published by the Massachusetts department of public works, including the insert maps on the reverse side thereof, in whatever form such route is indicated. A copy of this map is on file in the office of the state secretary. Section 2. Nothing in this act shall affect existing agreements, decrees, orders or statutes defining the duties, responsibilities or obligations of railroad companies or other public utilities relative to any such bridge so made a state highway. Approved June 4, 1948.