The local school district shall furnish transportation to pupils in kindergarten through grade 8 who live more than 2 miles from the school to which they are assigned. The local school district may furnish transportation to pupils in kindergarten through grade 8 who live 2 miles or less from the school to which they are assigned, and to pupils in grades 9 through 12, when it finds that this is appropriate, and shall furnish it when so directed by the commissioner of education.