Unless the rules on busing children to school have changed, where is it written that children have the legal right to be taken to school in a school bus? There may be factors that compel the district to bus schoolchildren to school, but it is not a right parents have.
Some research on this subject may be in order. Perhaps a carpool would be a consideration to ensure timely arrival at school.
If I am out of step, I will stand corrected.
