86.302(1g)(1g) Except as provided in sub. (1m), beginning on January 1, 2001, the board of every town, village and county, and the governing body of every city, shall file with the department not later than December 15 of every year, a certified plat of the municipality or county showing the highways under its jurisdiction and the mileage thereof to be open and used for travel as of the succeeding January 1. The department may use the plats in making computations of transportation aids. One-half of the mileage of highways on boundary lines shall be considered as lying in each municipality or county.

86.302(1m)(a)1.1. In lieu of filing a certified plat under sub. (1g), if a municipality or county has not added or deleted jurisdictional mileage since filing its last preceding certified plat under sub. (1g), its board or governing body may file a certified statement to that effect with the department.

86.302(1m)(a)2.2. Notwithstanding subd. 1., the department may require every municipality and county to file a certified plat under sub. (1g) with the department in the year after the year in which a federal decennial census is conducted.

86.302(1m)(b)(b) Upon incorporation of a village or city, the board of the village and the governing body of the city shall file with the department a certified plat of the village or city showing the highways under its jurisdiction and the mileage thereof to be open and used for travel as of the date of incorporation, which may be used by the department in making computations of transportation aids. One-half of the mileage of highways on boundary lines shall be considered as lying in the village or city.

86.302(2)(2) Not later than December 15, 2001, and biennially thereafter, each municipality and county shall assess the physical condition of highways under its jurisdiction, using a pavement rating system approved by the department and report the results of that assessment to the department. The department shall assess the accuracy of mileage or other data concerning highways reported by municipalities and counties and may use field investigations to verify a portion of the data constituting a valid random sample or such specialized sample as the department considers appropriate. The department shall cooperate with and provide assistance to local units of government in their efforts under this subsection. Information collected under this subsection is inadmissible as evidence, except to show compliance with this subsection.

86.302(3)(3) For the purposes of transportation aid determinations under s. 86.30, the department shall use changes in the highway mileage of a municipality or county indicated on the certified plat filed under sub. (1g) in making computations of transportation aids to be paid beginning in the 2nd year following the year in which the certified plat is filed. The department shall consider the following factors:

86.302(3)(a)(a) New highways.

86.302(3)(b)(b) Abandoned highways.

86.302(3)(c)(c) Changes in jurisdictional mileage responsibilities for existing highways.

86.302(4)(4) Islands of this state consisting of one or more towns shall receive all state aids regularly payable to towns under s. 86.30. For purposes of determining aids payable under s. 86.30, mileage under the jurisdiction of an island under this subsection includes the number of miles equal to the distance between an island port and the closest mainland port where such distance is regularly traveled by a licensed ferry transporting persons, cars, trucks, buses and other mechanized equipment.

86.303(4)(a)(a) The multiyear average costs used to determine the share of cost aids amount for local units of government shall be based on the 6 most recent years for which actual costs are available.

86.303(4)(b)(b) In the case of municipalities formed within the previous 6 years, the information needed for the determinations under this section shall be calculated as follows: for those years for which the necessary data does not exist, the data for the new municipality and the municipality from which it was formed shall be combined and the sum shall be apportioned to each municipality in proportion to the total mileage of highways under their respective jurisdictions. In making these calculations, the department shall use the certified plats filed under s. 86.302 (1g).

86.303(5)(ag)(ag) In this subsection, “working day” has the meaning given in s. 227.01 (14).

86.303(5)(am)(am) The department, with the assistance of the department of revenue and representatives of local governments and their associations appointed by the secretary, shall prescribe a uniform cost reporting procedure.

86.303(5)(b)(b) Cost data shall be reported on a calendar year basis, and financial report forms or a written request for extension shall be submitted to the department of revenue as provided under pars. (c) and (d). All extensions under this paragraph shall be until May 15 and no extension beyond that date may be granted.

86.303(5)(c)(c) The department and the department of revenue shall prescribe a statewide uniform financial reporting procedure under s. 73.10 for municipalities having a population of 2,500 or less. The financial report form or a written request for extension shall be submitted to the department of revenue by March 31 by municipalities having a population of 2,500 or less for the purposes under this section. All extensions under this paragraph shall be until May 15 and no extension beyond that date may be granted. The department of revenue shall forward the highway-related cost data to the department.

86.303(5)(d)(d) The department and the department of revenue shall prescribe a statewide uniform financial reporting procedure under s. 73.10 for counties having a population of more than 2,500 and municipalities having a population of more than 2,500. The financial report forms or a written request for extension shall be submitted to the department of revenue by May 1 by counties having a population of more than 2,500 and municipalities having a population of more than 2,500 for the purposes under this section. All extensions under this paragraph shall be until May 15 and no extension beyond that date may be granted. The department of revenue shall forward the highway-related cost data to the department. Counties having a population of 25,000 or more and municipalities having a population of 25,000 or more are required to submit a financial report form to the department of revenue under this paragraph and financial reports under par. (g).

86.303(5)(e)(e) Except as provided in par. (f), if a county or municipality fails to submit a substantially complete and accurate financial report form by the applicable date under par. (c) or (d) each year, the aids payable to the county or municipality during the following year shall be equal to 90 percent of the aids actually paid to the county or municipality under s. 86.30 (2) during the preceding year.

86.303(5)(f)(f) If a county or municipality submits a substantially complete and accurate financial report form within 30 calendar days after the applicable date under par. (c) or (d), the aids payable to the county or municipality for the following year shall be reduced by an amount equal to 1 percent of the aids payable to the county or municipality for the following year for each working day after the date required in par. (c) or (d) that the report form is actually submitted, subject to the following limitations: