605 ILCS 5/6-320

The highway commissioners shall also, in case a new township or district road is established on a county or district line, allot to each of such districts the part of such road which each of such districts shall open and keep in repair, and the part so allotted shall be considered as wholly belonging to such district. They shall also divide the expenses and damages which may accrue from such laying out, widening or alteration, and if they cannot agree, they shall refer the matter to the county superintendent of highways or in case the districts shall lie in 2 or more counties, the Department, whose decision shall be final.