Illinois question. Mother has no job. Stepfather has job. Biological father has visitation rights but lives abroad. Travel costs for visitation are high. Can the court force the stepfather to pay the travel costs of biological father for visiting child?

From what I read, no, but if the mother refuses or cannot pay the expenses can the mother be held in contempt of court? Yes.

Where did the father live when this order was issued (assuming it's in the US)? Or did the mother abroad and then come to the US with the children?

If the Order for travel expenses was somehow related to allowing the mother to move - depending on the Country - there could be another hearing with the father alleging that the mother took the children with the agreement that she would pay to return them for visitation.

No the stepfather can't be ordered to pay the costs, but the mother can. And if the mother doesn't pay she could go to jail for contempt of court. So while the step father can't be ordered by a court to pay those costs, the step father could be induced to pay them because of the risk to his wife.

Whether the court would order such costs be paid depends on a lot of factors that have not been provided. Like where did the bio father live with the visitation order was first issued. Where did the mother live? What does the visitation order say.

Mother was abroad. Foreign order gave custody and permission to move to US. Mirror order registered in US. US court amended order to split travel costs (Inc. International flight costs) 50/50. That was 2 years ago. Now Biological father venue shopping by asking judge in diff county to change order so 100% of all travel costs paid by mother. Biological father deliberately waits until 1 week before visit to confirm if he will see child, so flight costs go up from $1500 to around $5000.

First, the court where the mirror order was issued has jurisdiction. So, I don't see how he can get another court to rule on the case. So you just fight any change in venue.