1. At any time during the existence of a district, the board may submit to the voters of the district a proposition to increase or decrease the number of projects which it is authorized to complete.
2. If the board proposes to add one or more additional projects, the question shall be submitted in substantially the following form:
3. If the board proposes to discontinue a project, it shall first obtain approval from the commission if the proposed project is intended to be merged into the state highways and transportation system under the commission's jurisdiction or approval from the local transportation authority if the proposed project is intended to be merged into a local transportation system under the local authority's jurisdiction. If such approval is obtained, then the question shall be submitted to the district's voters in substantially the following form:
4. The board may modify the project previously approved by the district voters, if the modification is approved by the commission and, where appropriate, a local transportation authority.