1. Directors for urban school districts, other than those districts containing the greater part of a city of over one hundred thirty thousand inhabitants, may be nominated by petition to be filed with the secretary of the board and signed by a number of voters in the district equal to ten percent of the total number of votes cast for the director receiving the highest number of votes cast at the next preceding biennial election, except as provided in subsection 4 of this section.

2. This section shall not be construed as providing the sole method of nominating candidates for the office of school director in urban school districts that do not contain the greater part of a city of over three hundred thousand inhabitants.

3. A director for any urban school district containing a city of greater than one hundred thirty thousand inhabitants and less than three hundred thousand inhabitants may be nominated as an independent candidate by filing with the secretary of the board a petition signed by five hundred registered voters of such school district.

4. In any urban school district located in a county of the first classification with more than eighty-three thousand but fewer than ninety-two thousand inhabitants and with a home rule city with more than seventy-six thousand but fewer than ninety-one thousand inhabitants as the county seat, a candidate for director shall file a declaration of candidacy with the secretary of the board and shall not be required to submit a petition.

5. No candidate for election as a school board director representing a subdistrict as provided in section 162.563 shall be required to file a declaration of candidacy as provided in this section as the sole method of filing for candidacy.