105 ILCS 5/29-4
The school board of any school district that provides any school bus or conveyance for transporting pupils to and from the public schools shall afford transportation, without cost, for children who attend a charter school or any school other than a public school, who reside at least 1 1/2 miles from the school attended, and who reside on or along the highway constituting the regular route of such public school bus or conveyance, such transportation to extend from some point on the regular route nearest or most easily accessible to their homes to and from the school attended, or to or from a point on such regular route which is nearest or most easily accessible to the school attended by such children. Nothing herein shall be construed to prevent high school districts from transporting public or non-public elementary school pupils on a regular route where deemed appropriate. The elementary district in which such pupils reside shall enter into a contractual agreement with the high school district providing the service, make payments accordingly, and make claims to the State in the amount of such contractual payments. The person in charge of any charter school or school other than a public school shall certify on a form to be provided by the State Superintendent of Education, the names and addresses of pupils transported and when such pupils were in attendance at the school. If any such children reside within 1 1/2 miles from the school attended, the school board shall afford such transportation to such children on the same basis as it provides transportation for its own pupils residing within that distance from the school attended.
Nothing herein shall be construed to preclude a school district from operating separate regular bus routes, subject to the limitations of this Section, for the benefit of children who attend a charter school or any school other than a public school where the operation of such routes is safer, more economical and more efficient than if such school district were precluded from operating separate regular bus routes.
If a school district is required by this Section to afford transportation without cost for any child who is not a resident of the district, the school district providing such transportation is entitled to reimbursement from the school district in which the child resides for the cost of furnishing that transportation, including a reasonable allowance for depreciation on each vehicle so used. The school district where the child resides shall reimburse the district providing the transportation for such costs, by the 10th of each month or on such less frequent schedule as may be agreed to by the 2 school districts.
105 ILCS 5/29-4