(a) The State Transportation Board, or its successors, and the Department of Transportation are authorized to make such studies and estimates in connection with the location and relocation of highways, roads, streets, and rights of way in connection with the islands, whether within or without the islands, as may be necessary to the location or relocation of any roads, streets, or highways within or without the islands. The board and the department may, at the expense of the department, locate or relocate such roads, streets, and highways so as to conform to the plan of the authority for the development and improvement of the islands.

(b) The authority may grant rights of way and easements for highways and roads within the islands to the Department of Transportation, and the department is authorized and empowered to lay out, construct, improve, and maintain any such roads and rights of way. The cost of any such undertaking shall be deemed to be a proper and legitimate expense of the department.

(c) The State Transportation Board, or its successors, and the Department of Transportation are empowered to acquire, in any manner now permitted by law, real property, any interest therein, or rights of way for the location and relocation of highways and roads located in proximity to the islands and are authorized and empowered to expend any funds available to such board or such department for the purpose of such locating and relocating, and for constructing, improving, and maintaining any such highways and roads. The cost of any such undertaking shall be deemed a proper and legitimate expense of such board or such department.