On the petition of at least 10% of the legal voters residing in a road district (other than a county unit road district) to the district clerk, the clerk shall order a referendum on the proposition to increase the district’s rate limitation for road purposes under this Section and Section 6-505. The referendum shall be held at the next annual or special town meeting or at an election in accordance with the general election law. If the referendum is ordered to be held at the town meeting, the district clerk shall give notice that at the next annual or special town meeting the proposition shall be voted upon. The notice shall set forth the proposition and shall be given by publication in a newspaper published in the township, or if there is no such newspaper, then in a newspaper published in the county and having general circulation in the township, and by posting notices in at least 10 of the most public places in the township at least 10 days before the town meeting. If the referendum is ordered to be held at an election, the district clerk shall certify that proposition to the proper election officials, who shall submit the proposition at an election. The proposition shall be submitted in accordance with the general election law.
     Any road district voting after August 1, 1967, to increase its rate limitation for road purposes under this Section and Section 6-505 shall establish the increased rate limitation on a permanent basis.
     No more than 2 referenda authorized by this Section shall be held within any 12 month period. No referendum shall be held unless a petition signed by not less than 10% of the registered voters in the road district has been filed with the district clerk requesting an increase in the tax rate limitation for road purposes.