Alternative methods of providing transportation

121.555 (1) (a) is used and such transportation is under the immediate supervision of a competent adult. 2. A school operated by the school district or the private school has an actual interest in the safety and welfare of the children transported to the activity; 4. The school principal or other person with comparable authority authorizes such use. (b) 1. If transportation is provided to pupils and other persons in connection with any extracurricular activity of a public school under par. (a), the school board may make a charge for such transportation, to be paid by the persons transported, sufficient to reimburse it for the cost of providing the transportation. If transportation is provided to pupils and other persons in connection with any extracurricular activity of a private school under par. (a), the school board shall make a charge for such transportation, to be paid by the private school or the persons transported, sufficient to reimburse it for the cost of providing the transportation. 2. The school board may contract under s. 121.52 (2) (b) for transportation authorized under par. (a) for pupils attending public schools. The school board may authorize a charge for the transportation, to be paid by the persons transported, sufficient to make reimbursement for the cost of providing the transportation. (8) PAYMENT OF TRANSPORTATION COSTS. (a) The cost of providing transportation for pupils under subs. (1) to (6) and s.