Before the department proceeds with any action to secure a right-of-way or with construction of any toll bridge under the provisions of this chapter, the commission shall first pass a resolution that public interest and necessity require the acquisition of right-of-way for and the construction of the toll bridge. The resolution is conclusive evidence (1) of the public necessity of such construction; (2) that the property is necessary therefor; and (3) that the proposed construction is planned or located in a manner which will be most compatible with the greatest public good and the least private injury. When it becomes necessary for the department to condemn any real estate to be used in connection with any such bridge, the attorney general of the state shall represent the department. In eminent domain proceedings to acquire property for any of the purposes of this chapter, any toll bridge, real property, personal property, franchises, rights, easements, or other property or privileges appurtenant thereto appropriated or dedicated to a public use or purpose by any person, firm, private, public, or municipal corporation, county, city, town, district, or any political subdivision of the state, may be condemned and taken, and the acquisition and use as provided in this chapter for the same public use or purpose to which the property has been so appropriated or dedicated, or for any other public use or purpose, is a superior and permanent right and necessity, and a more necessary use and purpose than the public use or purpose to which the property has already been appropriated or dedicated. It is not necessary in any eminent domain proceedings under this chapter to plead or prove any acts or proceedings preliminary or prior to the adoption of the resolution hereinbefore referred to describing the property sought to be taken and directing such proceedings.