(1) A reduced incentive payment shall be made to any municipality or municipal county having appointed and employed either (a) a licensed city street superintendent for only a portion of the calendar year preceding the year in which the payment is made or (b) two or more successive licensed city street superintendents for the calendar year preceding the year in which the payment is made. Such reduced payment shall be in the proportion of the payment amounts listed in section 39-2513 as the number of full months each such licensed superintendent was appointed and employed is of twelve.

(2) Any municipality or municipal county that contracts for the services of and appoints a consulting engineer licensed under the County Highway and City Street Superintendents Act or any other person licensed under the act to perform the duties outlined in section 39-2512 rather than appointing and employing a licensed city street superintendent shall be entitled to an incentive payment as provided in section 39-2513 or to the reduced incentive payment provided in subsection (1) of this section, as determined by the Department of Transportation pursuant to section 39-2515.

(3) Any municipality or municipal county that contracts with another municipality, county, or municipal county for the services of and appoints a licensed city street superintendent as provided in section 39-2114 shall be entitled to the incentive payment provided in section 39-2513 or the reduced incentive payment provided in subsection (1) of this section.

(4) Beginning in calendar year 2022, a municipality or municipal county may appoint and employ a professional engineer who is licensed pursuant to the Engineers and Architects Regulation Act but is not licensed under the County Highway and City Street Superintendents Act and who is serving as city engineer, village engineer, public works director, city manager, city administrator, or street commissioner to perform the duties of city street superintendent outlined in section 39-2512. In such case, the professional engineer's license under the Engineers and Architects Regulation Act shall serve as a Class A license for purposes of incentive payments under sections 39-2512 to 39-2515. This subsection only applies to a professional engineer in the direct employ of a municipality or municipal county and does not apply to an engineer serving as a contractor or consultant.