In case the governing body of any city designated in section 14-1201, having been authorized by the electors as required in section 14-1251, shall at any stage of the proceedings determine to cooperate with any such properly authorized political subdivision in this or an adjoining state in the joint acquisition and operation of a bridge or bridges, a joint commission shall be created. Such joint commission shall be created and the members selected by the action of each political unit cooperating, in the same manner provided for the creation of a local commission by the statutes applicable to each political unit, and upon which representation may be proportioned to the respective contribution of funds by the political units cooperating for the purpose of such acquisition; Provided, that the total membership shall not exceed ten. The commission shall select a chairman and a vice-chairman to represent each political subdivision cooperating in the enterprise and shall maintain a single office at the place selected by the commission but for legal purposes shall be domiciled within the jurisdiction of each political unit cooperating and shall have the power to sue and be sued. This commission shall constitute a public body corporate and politic, shall select and adopt its own name, and shall be vested with such powers and subject to such conditions as may be conferred and imposed by the government of the United States and such powers and conditions in the State of Nebraska as are conferred and imposed in sections 14-1201 to 14-1252 upon a local bridge commission, and such powers and subject to such conditions in an adjoining state as may be conferred and imposed by the laws of such state. The plans and specifications, the location, size, type and method of construction, the boundaries and approaches, and the estimates of the costs of construction, acquisition of property, and financing, shall be first submitted to the governing bodies of the political units cooperating and receive their approval by resolution before final adoption by the commission, which shall not enter into contracts and shall have no power to proceed further unless and until such approval has been had. If such joint commission is created after any work has been done, any funds provided or any liabilities incurred by the governing body of the city or by a local commission, such joint commission shall take over, succeed to, assume and be liable therefor.