Ill. Admin. Code tit. 89, § 830.180
b) A student's local school district shall be charged for transporting a student home based on the following formula. The State shall be divided into eight concentric circles which are 50 mile wide bands with the center being Jacksonville, Illinois. Each concentric circle, beginning with the zone containing Jacksonville, Illinois, shall be numbered Zones 1 through 8. The circle number shall also act as the multiplier for determining the individual transportation cost for each student (i.e., Circle 1 shall have a multiplier of 1 compared to Circle 8 which shall have a multiplier of 8).
To determine the actual individual transportation cost for each student, the multipliers for all students who will be transported on the same bus will be added together and divided into the charge for the bus that will transport the students home. This will establish the base transportation cost. This base transportation cost will then be multiplied by the zone multiplier for the individual student to determine the actual transportation cost for the individual student which will be billed to the student's local school district.
(Source: Amended at 23 Ill. Reg. 10220, effective August 10, 1999)