After the determination by the county board, or a majority thereof, as provided by subsection (2) of section 39-1604, it shall call a special election and submit to the legal voters of the proposed road improvement district the question of the organization of such district and the election of a board of trustees who shall be resident taxpayers. Notice of such election shall be given as provided in subsection (1) of section 39-1604. At such election each legal voter resident within the proposed road improvement district shall have a right to cast a ballot with the words thereon, For road improvement district, or Against road improvement district. The special election shall be conducted by mail as provided in sections 32-953 to 32-959. The result of such election shall be entered of record. If fifty-five percent of the votes cast are in favor of the proposed district, such proposed district shall be deemed an organized road improvement district. At the same election there shall be elected three members of a board of trustees. Such members so elected shall be the first board of trustees of such district if the formation of the district is so approved at such election. Such board of trustees shall hold office until their successors are elected and qualified under the provisions of section 39-1606. It shall elect a president and clerk substantially as is provided for in sections 39-1606 and 39-1609.