N.J. Stat. § 48:12-43
Where a railroad is constructed across a stream where the tide ebbs and flows and by reason of the narrowness of the stream or shallowness of water it is unnecessary or impracticable to construct a pivot draw with 2 openings or any draw, the company may apply to the Department of Conservation and Economic Development, who shall, after personal inspection and due inquiry, determine what character of bridge is proper and whether any drawbridge is necessary and if so, the character and dimensions thereof and how the same shall be maintained, considering the extent and importance both of the navigation of the stream and of the public travel over the railroad.
The determination of the department shall be filed by it with the clerk of the county or counties in which the bridge lies and shall bind the company. A compliance with this determination by the company shall be a full performance of its duties and obligations with respect to the bridge.
N.J.S. § 48:12-43