The district may operate charter bus service subject to the following limitations:
(a) No bus equipment which is designed solely for charter service shall be purchased. A bus equipped with a toilet or underfloor baggage compartment shall be deemed charter equipment.
(b) The board shall hold a public hearing prior to adopting a charter rate schedule or any amendment thereof. Notice of the hearing shall be mailed to each charter-party carrier operating within the district at least 30 days prior to the hearing. The notice shall include the proposed charter rate schedule. At the close of the public hearing, the board may adopt charter rate schedules which shall not be less than the average for the three largest private charter-party carriers operating similar service in the district.
(c) Charter service shall originate and terminate within the area served by the district unless a private charter-party carrier requests the district to provide service beyond the area served by the district.