Idaho Code § 40-1401
Any county may, at the discretion of the commissioners, or shall, upon a request in writing from ten percent (10%) or more of the qualified electors residing in each of the county commissioner subdistricts, hold an election at which the following question shall be submitted to the electorate: "Shall this county be served by one county-wide highway district for all city highways and county secondary highways?". The election for this question shall be held at the next general election following a decision by the board of county commissioners for such an election or upon receipt of the qualified voters written requests to hold such election. At least one (1) public hearing shall be held by the board of county commissioners, prior to the election.
Idaho Code § 40-1401