advice on transportation ... Prek student rides the special education bus and the sibling (non iep) was granted permission from director to ride the bus with sibling (with iep). Child has separation anxiety and having the sibling ride with him ,helps tremendously. The new director has now told they cannot ride the bus with their sibling. Any tips on how to address this ? Or what questions should be asked ? 
 

thank you 

When you say director, so you mean director of special education?

I would gather data from professionals that without the sibling, the child will need additional resources provided on the bus (so why not just let the sibling ride along?) and that that without the sibling there would be school avoidance, which would lead to not providing FAPE.  And get it specifically written into the IEP as an accommodation.

If it's not in the IEP, the school doesn't have to do it.  I would have encouraged you to ask for this to be put in the IEP if you had posted when the decision was made to allow the siblings to ride together.  Do you have anything in writing, like old email, showing the thought process behind why this was decided?

I'm curious if there is any data showing your younger child had issues with anxiety on the bus (or with getting to school) before the sibling started riding with them.  IEP decisions should be based on data.  The accommodation of having a sibling on the bus might be providing access to their preschool IEP.  As they say in education:  If it's not in writing, it didn't happen.  This is why we encourage a paper trail of the things that are helping or trials that have failed.  It becomes proof in situations like this that the accommodation serves a bigger purpose than being a convenience for parents.